What does the BugSplat window mean?

It is the crash reporter that appears when Killing Floor 2 crashes. The steps below target the usual causes: a damaged config, damaged game files, a bad graphics driver or broken runtime libraries.

Which launch options help if the game will not start?

Try -windowed or -dx10 in the launch options of Killing Floor 2.

Fixes & Performance

Fix the Killing Floor 2 BugSplat Error: Config Reset and Driver Rollback

The BugSplat error is the crash dialog Killing Floor 2 shows when the game dies. This guide collects a short escalation path from a Steam community guide, plus extra tips from its comments.

Step 1: reset the config and verify files

Open This PC > Documents > My Games > KillingFloor2 and delete the Config folder. The game rebuilds it on the next start.
In Steam, open the game's Properties, go to Local Files and choose "Verify integrity of game files".

Step 2: roll back the graphics driver

If the error is still there, install an older version of your graphics driver (the author points GeForce users to NVIDIA's driver archive). Restart Steam afterwards.

Bonus: launch options

If the game refuses to launch at all, add -windowed or -dx10 in Library > Killing Floor 2 > Properties > General > Launch Options.

Tips from the comments

Persistent crashes were fixed for several players by reinstalling the Microsoft Visual C++ redistributable (vcredist), which can get corrupted.
If BugSplat keeps appearing after a mod install, see our related pages on BugSplat launch crashes and modded crash fixes.

FAQ

What does the BugSplat window mean?: It is the crash reporter that appears when Killing Floor 2 crashes. The steps below target the usual causes: a damaged config, damaged game files, a bad graphics driver or broken runtime libraries.
Which launch options help if the game will not start?: Try -windowed or -dx10 in the launch options of Killing Floor 2.