I'm not sure what percentage I get to before it crashes but I have updated to beta, reinstalled, reverified, installed latest NVidia driver, went back one driver. Also playing windowed and set graphics to low. I have attached the log files as well. But also for once I get a useful event viewer error.
Faulting application name: BattleTech.exe, version: 5.6.5.64727, time stamp: 0x5a5de904
Faulting module name: ffmpeg.dll, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000005
Fault offset: 0x00000000000b5a4c
Faulting process id: 0x14c4
Faulting application start time: 0x01d3e0cb41e043de
Faulting application path: C:\Program Files (x86)\Steam\steamapps\common\BATTLETECH\BattleTech.exe
Faulting module path: C:\Program Files (x86)\K-Lite Codec Pack\Filters\ffdshow64\ffmpeg.dll
Report Id: c30b8957-4cbe-11e8-8000-fcaa14946028
From reading this I have an access violation error and I have full write access to both folders and running the battletech.exe as admin is set. I notice that system tray icons for various K-Lite decoders come up during the start of the new campaign. The game start video doesn't have a problem but maybe the new campaign video does.