Cannot Start JetBrains Rider with System.BadImageFormatException

Symptoms

JetBrains Rider can unexpectedly close without any error messages. Upon attempting to relaunch Rider, users experience a "Critical Failure Has Occurred" message.

User may also encounter the following error:

C:\Program Files\JetBrains\Rider\r2r\2024.2.0EAP\FB97271D721C429643ABF6FDA82AFE0\windows-x64\Rider.Backend.exe --runtimeconfig C:\Program Files\JetBrains\Rider\r2r\2024.2.0EAP\FB97271D721C429643ABF6FDA82AFE0\Rider.Backend.windows.runtimeconfig.json --Port=51472 --enablecpp
Unhandled exception. System.BadImageFormatException: Bad IL format.
   at JetBrains.Rider.Backend.Product.RiderBackendWatchdog.Start()
   at JetBrains.Rider.Backend.Product.RiderBackendProgram.<>c.<Main>b__4_0(Lifetime lifetime)
   at JetBrains.Lifetimes.Lifetime.Using[T](Func`2 action)
   at JetBrains.Rider.Backend.Product.RiderBackendProgram.Main()

This error can persist even after attempting to uninstall and reinstall the software. However, reinstalling the correct version of the software may solve the problem momentarily.

Cause

Rider backend process is unable to start, resulting in the System.BadImageFormatException: Bad IL format error.

1. There is a mismatch in the versions of the used software and operating system.
2. Either Rider files or the .NET runtime installation are damaged.

Resolution

Users should first check the version of JetBrains Rider they are using. Ensure it matches the architecture of the operating system where it's being installed.

After checking the JetBrains Rider version and OS architecture compatibility, the next step is to try uninstalling and reinstalling Rider.

If the issue persists, run a system file checker scan to search for and repair any corrupt system files in Windows.