• iRacing may generate a log, look for similar to /documents/iRacing/iRacingSim64_20h55m38s.log
• You can also check windows logs; see iRacing's FAQ article 99.
  
• Reports can be emailed to support@iRacing.com (include session details, system info, description of events).
• For my reference, from FAQ for windows 7:
  Win+R >  "eventvwr" > Windows Logs > Application > Look for "Error" > Copy report from general tab
  
• Staff post  
  

  Got which error? There seems to be some confusion about windows error reporting. Essentially all crashes are "application errors" and "memory errors". What differentiates them are the exception code, exception offset, address accessed. All crashes are not the same just because they happened in iRacing and the application was terminated due to accessing an incorrect memory address.
  
  To help us to identify each unique issue we require the information specific to the "application error" or "memory error". This information includes the crash .log file if available, and/or the windows event from the windows event viewer, along with a description of what you were doing when it happened such as session type, car and track, configuration files, dxdiag.exe text outputs, etc. The more info we receive the easier it is for us to identify and fix individual issues.

  Also see Report checklist at bottom of page
  
  

• If you're keyboard isn't responding as expected in sim, try pushing the ALT key once (to turn it off - weird).
  A new (related?) keyboard bug 2015, Buttons and keyboard sometimes stop working on the grid thread.
  David T (iR Staff) screenshot.
  
• If your cursor is in the text box, it may prevent keys / buttons working in sim. (eg can't key up mic).
• iPad not displaying embedded youtube clips on forum: click last "A" top right of forum screen .
  After a recent iOS update the above line doesn't change the way youtube displays (which is small). Any fix?
  

• iRacing added EAC's program Sept 2015 (Season 4) thread.
• RadeonPro uses an injection method which can't be white-listed (post, post).
  Post: If you are using RadeonPro to reduce input lag caused by pre-rendered frames,
  in case you have NVIDIA graphics card, you can set the number of pre-rendered frames to 0 from the NVIDIA control panel
• SweetFX issues, too many threads/posts. Try SweetFX not working thread and the Oculus Rift thread.
• Error 73. Post | Screenshot.
  According to EAC, this error would come up if your iRacingSim.exe or iRacingSim64.exe fails the digital signature check.
• Hangs on "Validating Installation" thread 
  Aarni suggested in post, check you can access http://download.eac-cdn.com/testconnection/
  See thread for more. 
  

• For reference, the old FAQ.
  
• Post by Randy C (11/2015):
  " Port ranges were not changed during this work. They're still [15000..52499] (inclusive). 
  If you can list hostnames, that's best. Use somrace##-orig.iracing.com, with ## being 01, 02, ... 10 (for now, anyway).
  If you can specify IP/mask, that's second best: For the US farm, you can use 69.25.78.0/24.
  If you have to list specific IP addresses, use 69.25.78.241, 69.25.78.242, ... 69.25.78.250 (for now, anyway).
  Note that IPv6 support will be coming soon. With any luck, you'll be able to specify that with CIDR notation (something like 2001:db8:beef:f00d::/64), if you can't specify hostnames. The specific IPv6 address/mask range is still being mapped, so don't use that! (Bonus points if you say why that example address couldn't possibly be what we'll use). "
  
• Related post by Randy C (11/2015):
  " Complete networking switchover/upgrade in our main datacenter.
  New internet circuits, new firewalls/switches, retired the old equipment.
  If you ever ping/tracert our US servers, they're all at new addresses.
  It'd be best for you to use hostnames instead of IP addresses.
  somrace01-orig.iracing.com
  ...
  somrace10-orig.iracing.com
  
  The remote servers have hostnames, too.
  amstrace01-orig.iracing.com
  ...
  amstrace03-orig.iracing.com
  sydrace03-orig.iracing.com
  ..
  sydrace04-orig.iracing.com "
  

• Internet Explorer: microsoft.com
  
• FireFox: mozilla.org
• Google Chrome: google.com
• If iRacing's website doesn't load properly, try deleting cache.
  Next, try viewing in a "private" or "incognito" window in your browser.
  

• 
  
• Posted by iRacing staff:
  

  If you are using Internet Explorer, please see: http://windows.microsoft.com/en-us/internet-explor...ory-internet-explorer#ie=ie-11 for more details.
  Also, in IE, go to Internet Options...then click the Security tab...click Trusted sites and then click the Sites button.
  First uncheck "Require server verification..." and then add the following 3 sites:
  http://members.iracing.com
  https://members.iracing.com
  http://127.0.0.1
  and then recheck the "Required server verification..." and then Close.
  If you are using Firefox, please see https://support.mozilla.org/en-US/kb/remove-recent...ry#w_how-do-i-clear-my-history for more details.
  If you are using Google Chrome, please see: https://support.google.com/chrome/answer/95537?hl=en for more details.
  Also, please uninstall/disable any unnecessary add-ons and extensions that are installed on the browser. "

• Susan F post (2015s3)
• Windows Method 1:
  Open C:/Program Files (x86)/iRacing/msvc folder.
  Run vcredist_x86.exe
  If it prompts you to Repair, Remove or Close - choose close.
  Then do the same for the file vcredist_x64.exe. 
• Windows Method 2:
  Delete a car or track from C:/Program Files/iRacing/Cars
  Go to members site to redownload and install.
  When reinstalling it will prompt you to then install the Microsoft Visual C program which is needed. 
• MAC - see above post and links
  

• Nothing noted in iRacing FAQ when I checked.
• Post by Susan F (iR Staff), in part says:
  Please be sure these files are being allowed through your firewall and/or antivirus software
  (ED: Due to my website CMS the slashes below are reversed)
  C:/Program Files/iRacing/iRacingService.exe
  C:/Program Files/iRacing/iRacingSim.exe
  C:/Program Files/iRacing/iRacingLocalserver.exe
  C:/Program Files/iRacing/iRacingChat.exe
  C:/Program Files/iRacing/iRacingLauncher.exe
  C:/Program Files/iRacing/updater/iRacingUpdater.exe
  ***If you are using a 64bit version of either Windows 8, Windows 7, Vista, or Windows XP, please allow these files firewall and/or antivirus software
  C:/Program Files (x86)/iRacing.
  C:/Program Files (x86)/iRacing//RacingService.exe
  C:/Program Files (x86)/iRacing /iRacingSim.exe
  C:/Program Files (x86)/iRacing /iRacingSim64.exe
  C:/Program Files (x86)/iRacing /iRacingLocalserver.exe
  C:/Program Files (x86)/iRacing /iRacingLocalserver64.exe
  C:/Program Files (x86)/iRacing /iRacingChat.exe
  C:/Program Files (x86)/iRacing /iRacingLauncher.exe
  C:/Program Files (x86)/iRacing /updater/iRacingUpdater.exe ******
  Then reboot your computer
  Log back onto the members site and try to launch a test session.
  
• Also note: if your IP (internet address) keeps changing it could cause a problem with the iRacing system verifying it's the same computer. Logging out and back in could resolve it till it happens again.
  

• Windows 7 or Vista:
  Windows start button > All programs > iRacing > "Start iRacing service".
  After black box opens/closes, reload your browser on the Members page.
  
• Windows 8:
  Press Windows icon AND E on keyboard
  Select computer
  Open C drive
  Open 'Program Files' or 'Program Files (x86)'
  Open iRacing folder
  Execute Start_iRacingservice.bat
  After black box opens/closes, reload your browser on the Members page.
• Post by Susan F (iR Staff).
• Related iRacing FAQ article.

• If you are getting the following error:
   
  " The following error occurred while trying to join the session:
  Failed to verify signature on program executable. "
  
  What this means is that for some reason your executables do not have the proper digital signatures on them.
  
  What might help is to delete the version_system.txt from the iRacing installation then the web­site should ask
  you do redownload and install the system package again.
  
  If you have any problems updating through the web interface, try navigating to your
  C:/Program Files (or ProgramFiles x86)/iRacingUpdate and double click the iRacingUpdater.exe
  Once that runs and you click Done, go back and refresh your browser.
  It should now say you are Up To Date

• Post by David T. "You get this message when the wheel turns a lot more in one direction than the other. Either you are failing to return the wheel to the true center during calibration, or the wheel has slipped a tooth on its bump stop and is no longer symmetrical. You should be able to figure out what is going on by watching the numbers while calibrating. During the step when we ask you to turn the wheel all the way left, then right, then back to center make sure that the numbers come out something close to 0, 16,000 and 8,000 (for this wheel) and make sure that we report the percent at around 50% when setting the center point".
  
  
• Post by David T. "... the problem is that the measured center of the wheel was significantly different than the calculated center of the wheel.
     Usually this is caused by a mistake when calibrating. When we ask you to turn the wheel all the way to the left, then all the way to the right, then return it to center, if you miss any of those three steps you will get this message. You turn it all the way left and right so we can detect the wheels min and max value, or range, and you return it to center to tell us what way you think is up.
     Often people forget to turn the wheel all the way to the right, or they get caught out on 900 degree wheels, not realizing that there are three wheel locations that look centered, but only one of them is the center of steering travel. This is especially problematic on wheels that don't play a centering spring force when they are not in use. I suspect that the T300 is one of those wheels.
     It is possible for your wheel to be physically broken so that it turns farther in one direction than the other, or more likely so the electronics report rotations farther in one direction than the other, but that is unusual".
  
  
• Post by David T. "... when you changed your wheel to 1080 degrees, did you re-calibrate in iRacing? Each car in the sim has a fixed amount of steering rotation, depending on the steering ratio and the stops at the tires. Most cars probably only support 450 degrees of rotation, although the VW Jetta supports the full 1080 degrees.
     Anyway if you tell us properly that your wheel supports 1080 degrees of rotation, by turning your wheel 90 degrees to the left during calibration, then we will add in our own steering locks at 450 degrees, or whatever the car needs, and only use a small range of the motion. If you limit things to only 250 degrees then we have to play games to map 250 degrees onto 450 degrees (or whatever) and you will get non linear steering that is a bit darty. You can make anything work, but you will be happier in the end if you can get use to using the full wheel range".
  

• "Program files (x86)" may be "Program files" depending on your windows system.
• Setups and replays located in My Documents/iRacing/Setups and Replay folders. Should be safe or back up to be safer.
• To save time and bandwidth, you can copy C:/Program Files (x86)/iRacing/Cars and Tracks folders to another location.
  Then after deleting and reinstalling the iRacing program, before doing the download/updates - replace the new Cars and Tracks folders with the original ones. Then go back to the iRacing Members site and click Refresh. You may still need to do a small update but it will be much quicker.
  
  
• Steps:
  * Control panel > Add/remove Programs > remove iRacing
  * Delete folder C:/Program Files (x86)/iRacing
  * Empty recycle bin
  * Reboot computer
  * Open http://members.iracing.com follow download/update/install instructions

• Posted by Randy C August 2014 (I haven't tried doing it);
  All you really need to do is:
  Open the current installation folder.
  Double-click the Stop_iRacingService batch file.
  Copy the iRacing folder to the new location
  In the new location, double-click the Start_iRacingService batch file.
  Doing this tells Windows where to find the iRacingService so that it can be started up when Windows boots up.
  Verify that everything works properly. Take a few days or a week if you don't immediately need the extra space.
  Once you're sure everything is working, delete the "old" iRacing installation folder.
  
  But note that you should NOT move the contents of the iRacing folder to the root of a disk.
  So, for example, you would not want to have D:/iRacingSim.exe.
  Copy the iRacing folder itself to the root of the disk (if that's where you want it). So that you have D:/iRacing/iRacingSim.exe.
  
• Change path of REPLAYS
  Auto backup replays and setups thread to Dropbox.com using symlinks. Interesting reading at howtogeek.com. (Discussed in reddit post too).
  

• Loading error 71 iRacing FAQ.
• Loading error 72 iRacing FAQ.
  
• Loading errors 71 and 72 thread has been resurrected. Screenshot for my reference.
  Another post by Randy C was to the point
  
  The most likely cause for these errors is a bad/failing disk drive, or flaky data cable.
  
  The second most likely cause is bad/failing RAM, or RAM or a CPU that's overclocked too much to be stable.
  
  To protect against these types of errors causing deeper/harder to find problems, we hash the car&track data files before we read anything from them, and compare the hashes against the known-good values. These two errors indicate that the computed hashes are incorrect. If it was because of an error in the code, or an error in our known-good hashes, pretty much everyone on the service would hit the same issue all the time. 
  
  
• Loading error 62 staff post by Randy C:
  "Error 62 means the sim could not internally switch to the directory in which the track is located, in preparation for loading the track. I imagine this could be for any part of the directory tree needed to get the track loaded (so everything from iracing/tracks/... downward along the path to the specific track you were trying to use)."
  
  
• Loading error 40 staff post by Randy C:
  "40 means it couldn't load some piece of graphics needed by the sim's user interface. It might help to remove the file named version_system.txt in the sim's installation directory (by default, this is C:/Program Files (x86)/iRacing). Then, refresh your browser and the web site will tell you that you have required updates. Allow it to download and install the update. If that doesn't fix the issue, contact support@iracing.com."
  

• I don't understand how this helps, read the thread:
  Randy C post. You can also try changing a setting in My Documents/iRacing/core.ini. Double-click on core.ini to edit it in Notepad, and near the top, in the [Communications] section, change the following value to 1 instead of 0. connect_sockets=0
  Read the thread for further information.
  

• Post by Randy C.  My edit:
• - Run sim in window mode.
    Open sim > Options/Graphics page > un-check [ ] Full Screen Option > click done > exit options > exit sim
  - Using notepad, edit My documents/iRacing/app.ini
    In [Graphics] section, change deviceIdx=0 to deviceIdx=1
    (I have more notes about app.ini)
  - Open sim > Options/Graphics page > check the [X] Full Screen checkbox.
    Window Resolution dropdown should now list resolutions for your second monitor.
    Choose the resolution/pixel depth you want.
    Click Done to leave the options screen then exit the sim.
  The next time you launch the sim it will appear in full-screen mode on your 2nd computer.
• Another post by Randy C.
  Trying to get a specific monitor of 3 to display iRacing:
  [Graphics]
  deviceIdx=1
  "Edit this file while the sim is not running. Change the value to 2. Save the file then launch the sim. If that's still not the correct monitor, exit the sim, and edit the file again so the value is 3. Once you've found the correct monitor, you can then change the graphics settings in the sim to match the monitor's resolution and run the sim full-screen".
  

• Post by Randy C.  My edit:
• An iRacingService program running in background generates car images for your web browser.
  It builds them from a data file in your installation directory for the specific car.
  The data file in C:/Program Files (x86)/iRacing/httproot/cars/astonmartin directory may be corrupt.
  (Or the relevant folder for the car with an issue).
  The suggested fix:
  Delete the contents of that directory, then refresh browser.
  You should be told you have required updates.
  Apply update and keep your fingers crossed.

• 2016s2 Voice chat issue, staff post by Daniel G.
  "There is a problem with voice chat not being included in the data coming from the client in some cases.
  It is a bug that went undetected because it incorrectly relied on the broken behavior that was just recently fixed!
  I expect we'll be putting together a fix for you ASAP."
  Update:
  2016s2 patch 2.1:
  "- Fixed an issue that could have caused your own voice chat to be discarded instead of being sent to the server, especially if your bandwidth selection, in the "My Account/Preferences/Connection Type" dropdown on the website, was at the default "128K or faster" selection (which is the minimum value). "
  
• If you change "playback" device in the sim options, you need to exit the session and rejoin.
• Voice chat not working: Check "Connection type" near bottom of your iRacing account page isn't set to "dialup".
  
• "when spotter speaks the engine volume goes down" thread - turn off Smart Volume in Sound Blaster Cinema app.
• Realtek HD Audio Manager: untick "Loudness Equalization" image.
• Windows sound properties image.
• Voice chat volume post by David Tucker. Noted from his post...
  Some sound cards behaving differently than others; 2 workarounds:
  Use headphones for the voice chat and speakers for the rest.
  That way you have separate external volume controls for each output.
  The other way is to exploit a fix we put in for surround sound setups.
  In a surround sound setup iRacing lose control over the mixing of the sounds, it's all up to the sound card.
  However in surround sound mode iRacing still mix the engine in stereo because it sounds better with the samples they have.
  So iRacing have complete control of the engine volume but no idea how loud the rest of the sounds are playing,
  on some sound cards that can result in your engine being crazy loud (or quiet).
  So iRacing have a fix in the app.ini
  [Audio] stereoStreamInSurroundBalance=1.0, by setting that to 0.5 you will be cutting the engine volume in half.
  However, that may also cut the voice chat volume, but I think it does not.
  
• Re MX5 (and other cars) sound issues. Staff post April 2016.
  "This issue was raised a few weeks ago but I can't find the post now. When we get xAudio2 this should fix a lot of these random static/crackle issues and we can have more sounds and higher rates plus dsp effects. So iRacing are on to it and want to fix it. I have no idea when this will happen but I want it as badly as you guys! I have worked on other titles that have similar issues. I can assure you it is not in the actual sound samples, but there are a few extremely faint ghost sounds where I removed a truckload of rock sounds from the original MX5 2016 recordings.
  I will have another look at those MX5 tire sounds, there is a bit of noise but it's not always apparent. Some soundcards and audio gear present these artifacts more than others and people with headphones are going to hear these things pretty well.
  The engine sound sample rate is 48K, and the incar sounds are in stereo. so up the rate in the app.ini if your system can handle it. Our new sound system will allow higher rates by default in the app.ini "
  

• Source: posts by Shannon W in thread (2nd June 2015).
• The only known issue is with their new browser and it recognizing that iRacingService is running. I've been running 10 since the beta started, no issues with iRacing.com
• Post. I would hope MS fixes it cause the issue is on there end contacting localhost.
  If you are using 10 and Spartan, here is a workaround.
  Open cmd shell in admin mode
  type or paste in this
  CheckNetIsolation LoopbackExempt -a -n=Microsoft.Windows.Spartan_cw5n1h2txyewy
  

Posted by iRacing staff / Alex G. (29 Jan 2016)

Hello everyone,

If you are having stuttering frame rate issues (your frame rate is inconsistent at times), here are some steps you can follow that may help. We have identified a number of different things that could be causing problems, some of which we have fixed in our recent updates. However, iRacing is a graphically demanding and CPU-intensive application, and it must run in a constantly changing environment, with many versions of operating systems, device drivers, and other differences between systems. These steps may not solve all your issues, but they have been found to help a majority of those with stuttering issues.


BASIC STEPS:
These are the first steps to try. If these solve your issue, great! If not, there are more steps below.

01) If you are using a 64-bit enabled Windows machine, ensure you are using the 64-bit version of the Sim.
To check what type of Windows machine you have, right-click on "Computer" on your desktop, and select "Properties". Then, under the "System" heading, the "System type:" will inform you if you have a 32-bit or 64-bit operating system.
To enable the use of the 64-bit version of the Sim, go to the iRacing.com website and click on the "Settings" menu option. Then, make sure the "64-BIT MODE" slider is set to the "ON" position.

02) Shut down your machine completely, and then turn it back on.
This will ensure your computer's available memory space is maximized, and that no other programs are running.

03) Once your machine has booted up, launch your web browser of choice and go to the iRacing members site.
Avoid launching other applications that might utilize some of your machine's processing power.

04) Run the Automatic Graphics Configuration tool by clicking on "Settings" on the iRacing website, and clicking "Launch" next to the "RUN GRAPHICS CONFIG" option.
This configuration tool will automatically analyze your machine specs, and adjust your Sim graphics options to best match the capabilities of your machine.

05) Run the iRacing Sim and observe your frame rate for stuttering.
If the graphics are smoother now in the situation(s) where they struggled previously, you’re done!


NEXT STEPS:
If you are still experiencing stuttering, continue with these steps.

06) In the iRacing Sim, select Options, then Graphics, and enable the "Frame Rate: Limit AC" option and set a "Limit AC" value well below 200. For example, try 83 to start. Also, set a "Batt" value to 60.
Holding the mouse cursor over these options will explain what they do at the bottom of the screen.

07) In your Graphics Options, Set the "Max Prerendered Frames" option to 1, unless your system is using Crossfire or SLI, then set it to 2 instead.
If you are unsure about whether or not your machine has Crossfire or SLI technology and if it is enabled, please browse AMD or NVIDIA documentation respectively.
If you are unsure which brand of graphics card your machine has, open your Device Manager and expand the "Display adapters" node to view the graphics card(s) installed on the machine.

0 In your Graphics Options, Reduce your "Max system memory to use" slider to no higher than 4000MB, no matter how much memory your machine might have.
Reducing the maximum system memory being used by the iRacing Sim is a good way to ensure your system is able to run background tasks that might otherwise slow down the iRacing Sim.

09) Now click “Done” on the Graphics Options display, and exit the iRacing Sim.
Exiting the iRacing Sim ensures that all of these Graphics Option adjustments are applied.

10) Run the iRacing Sim and observe your frame rate for stuttering.
If the graphics are smoother now in the situation(s) where they struggled previously, you’re done!


ADVANCED STEPS:
If you are still having frame rate stuttering issues, browse through these adjustments for the individual steps that directly apply to your specific issues and system setup. Be sure to read them carefully before following any of them.
Important Note: After making any adjustments to the Graphics Options in the iRacing Sim, you must exit and restart the iRacing Sim completely in order for the changes to take effect.

I seem to have stuttering only when people join my session:
- Exit the iRacing Sim.
- Edit "LoadTexturesWhenDriving" to "=0" in your "renderer.ini" file, which can be found in your “My DocumentsiRacing” folder.
- Edit "showJoinLeave" to "=0" in your "app.ini" file, which can also be found in your “My DocumentsiRacing” folder.

I have a stutter exactly every 5 seconds:
- In your Graphics Options, reduce all of the Memory sliders.
- Uncheck the "Render Dynamic Track Data" option box.

I am using Crossfire or SLI on a Windows 10 machine and experience massive FPS loss and stuttering in full-screen mode, but it appears to get better as the session goes on:
- In your Graphics Options, uncheck the “Full Screen” option box.

I have a 4GB 970-series graphics card:
- In your Graphics Options, reduce your "GPU Video Memory" option slider to a value less than 2500MB.

The stuttering seems to always get worse the longer the session lasts:
- In your Graphics Options and Replay Options, set the "Particles" option to the "Low Detail" value.

I seem to only be having stuttering at the Nürburgring GP:
- In your Graphics Options and Replay Options, enable the "Cockpit Mirrors Max" option and reduce the number of mirrors.
- Uncheck the "Virtual Mirror" option box.
- Reduce the values of some or all of your graphics "Detail" settings to "Medium Detail" or lower.

I have a three monitor setup and I seem to only be having stuttering at the Nürburgring GP:
- In your Graphics Options and Replay Options, enable the "Cockpit Mirrors Max" option and reduce the number of mirrors.
- Uncheck the "Virtual Mirror" option box.
- Reduce the values of some or all of your graphics "Detail" settings to "Medium Detail" or lower.
- Uncheck the "Render each screen separately" option box. 

• The iRacingService (iRacing.com Helper Service) post by Randy C (9/2015). Screenshot.
  
• "Screen Freeze Problems Identified" thread - an old thread which may be misleading.
• "Verification failure" thread.
• Surround Sound post by DT is interesting reading.
  
  We do output proper surround sound when driving, and when viewing a replay. I'm guessing the reason you don't hear it that well when driving is that your cards are squishing the sounds together. Keep in mind that we are placing the tire sounds only a few feet from your head when driving. My experience with sound cards is that when a sound gets too close to the mic the card starts to behave strangely. Battle field or whatever game is probably separating the sounds out so they are located far away, even if graphically the sounds are placed close to your head.
  
  One of the core problems is that the sound card needs to know if they are mixing down to stereo speakers or stereo headphones or to surround sound speakers, and windows does a poor job of reporting those modes. I suspect to make the sounds not totally stink the sound cards bake in some sort of hybrid mode that sounds ok in all configurations, even if it is not technically correct.
  
  Anyway this is why we want to go to XAudio2, so we have full control over the sound mix. Right now we have full control over stereo (and it sounds good), but no control over surround sound (and it is very inconsistent) but with xaudio we would be able to fine tune the mix to any number of speakers. It would still be up to the user to properly report what equipment they have, and I suspect that fancy surround sound headphones will not behave that well, but we at least could drive those in stereo mode.
  
  Ideally we would combine xaudio2 with our own head related transfer function so we could mix from stereo to simulated surround and gain full control of the whole process.
• Sound: Not directly related to above, an interesting thread with reference to DD Live and DTS Connect.
• Gained time bug posted by Randy C (14 Oct 15) - a fix to come.
  
  "The "gained time" stuff is done on the client, and it communicates the infraction to the server (it's one of the few "race control" things done on the client). Unfortunately when spotters were added, and later when team racing was added, that code did not get disabled for "crew members". So your crew members are using their extrapolated positions for you car while evaluating the rule, and sending the infractions for your team to the server. Only the team member that is currently driving the car should be evaluating these rules - that's what we're fixing."
  Source: http://members.iracing.com/jforum/posts/list/3335413.page#9297181
• DirectX Visual C Runtime. Posted by Randy C (6 Oct 16).
  
  It's generally sub-optimal to go dropping things into your system directories that you've downloaded off random sites on the Internet (or been emailed, dropboxed, whatever). If possible, either remove or rename the "bad" files that are already in your system directory, and use the official Microsoft DirectX installers (either the copies we distribute, or grab them from Microsoft). Only directly drop files into the system folders as a last resort, and understand the risks involved in doing so.
  
  For reference, our updater runs the proper Microsoft installers for things if it sees that some file is missing that is added to your system by that installer. We only look for the presence of the file - we do not ask Windows to verify the validity of the file.
  
  We run the DirectX installer if any of these are missing:
  d3dx9_31.dll, d3dx9_43.dll, D3DCompiler_43.dll, xinput1_3.dll
  
  We run one or more of the Microsoft Visual C Runtime Library installers if one of the following files is missing:
  msvcr120.dll, vcruntime140.dll
  
  We look for these files in the <windows>System32 folder, and on 64-bit windows also in the <windows>SysWOW64 folder.