This error is caused by trying to load a spotter sound file.

 

If you are using a custom spotter package, this may be corrupted or broken in some way.

Please report this error to wherever you got that custom spotter pack.

If you are using a spotter pack that comes with iRacing, please let us know which one, and we can investigate further.

In the meantime, to get past this error, please try and back up your current app.ini file (located in your Documents/iRacing folder) or rename it to app.ini.old.
Then the next time you launch the sim it will create a new app.ini file.

If that doesn't help, please try and reinstall the iRacing software.
The best way to reinstall iRacing is to first remove it from your Control Panel...Add/Remove Programs.
Then delete the C:\Program Files (x86)\iRacing folder.
Empty your Recycle Bin.
Then reboot your computer.
After that, log back into iRacing and follow the download/install/update instructions.
Although your setups and replays should not be affected in this process, if you feel more comfortable, you can back up your My Documents/iRacing/Setups and Replay folders first.

To save time (and bandwidth), you can back up your 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.

You can also find this information in our FAQ: CLICK HERE

Please let us know if we can be of any further assistance.