Since new patch i experience problem with the file perf.dat.
After normal game session (except when alt-tab crashes occurs), when i launch crpg and try to rejoin a game, I can't and get a crash message.
The only solution I have at this point is to delete the file : "C:/User/<Login>/AppData/Roaming/MountAndBladeWarband/perf.dat" to let the game generate a new one.
Potentially corrupted ? I don't think because I haven't any problem with native.