This is more of an inconvenience than a real problem, but I'm describing it anyway in case other people have the same thing.

CP77 runs fine on an external hard drive, but when I reinstalled for 2.0 I put it on my SSD instead. I'm on Windows 10 and this is my system drive. Clean install, no mods. When I try to launch, I get the Flatline error message and nothing else.

I use Gog's verify/repair option and it detects something is missing and downloads 38 MBs. But the thing is it does that every time I try it. I can verify over and over and it downloads 38 MBs every time. Doesn't fix the problem.

The crash logs say that "The thread attempted to read inaccessible data at [pointer]."

So it seems like the installer is trying and failing to write to a location where it doesn't have permission, or there are some files that are... getting erased? for some reason? It's not Windows Defender or my antivirus software, I know that. There's nothing obviously wrong with the permissions in the game folder or files. I tried some fixes from other crash threads like deleting user config files etc. Other games on the same drive don't have this issue.

...so I gave up and reinstalled it to an external USB drive and it runs fine. (It's annoying though because sometimes when I'm driving around in game, the models and textures for new areas can't load in fast enough. Separate issue.)

Maybe somebody going through the same troubleshooting process will read this and save themselves some hassle. But I would like to get it running on my SSD if I can.

The crash log:

Registered crash info file...
InternalVersion: 3.0.4902785 P4CL: 6408866 Stream: //R6.Root/R6.Release
!!!CRASHED!!!
Error Reason: Unhandled exception
Expression: EXCEPTION_ACCESS_VIOLATION (0xC0000005)
Message: The thread attempted to read inaccessible data at 0x26C6BCFAAC0.
File: <Unknown>
Line: 0

"uptimeSeconds":1
"stopThreadID":6992
"exceptionCode":0xC0000005
"processID":15276
"Engine/CommitFailedErrorCode@1#TID=0":"0"
"Configuration/Name@2#TID=0":"FINAL"
"Configuration/Name2@3#TID=0":"FINAL"
"Game/Patch@7#TID=0":"2.0"
"Engine/OOM@4#TID=0":"false"
"GlobalMode/IsClosing@5#TID=0":"false"
"GlobalMode/IsGame@17#TID=0":"true"
"Jobs/InitParam/MaxLatentJobs@8#TID=0":"131072"
"Jobs/InitParam/MaxCriticalPathJobs@9#TID=0":"65536"
"Jobs/InitParam/MaxImmediateJobs@10#TID=0":"2048"
"Jobs/InitParam/WorkerThreadStackSizeKB@11#TID=0":"1024"
"Jobs/InitParam/MaxThreads@12#TID=0":"27"
"Jobs/InitParam/AllJobsCriticalPath@14#TID=0":"false"
"Jobs/InitParam/UseJobDebugger@13#TID=0":"false"
"Jobs/Dispatcher/NumDispatcherThreads@15#TID=0":"11"
"Jobs/Dispatcher/MaxHWConcurrency@16#TID=0":"12"
"Engine/SafeInit@112#TID=0":"DebugFilters"
"Engine/IsHeadless@108#TID=0":"false"
"Engine/VersionWatermark@107#TID=0":"3.0.4902785 P4CL: 6408866 Stream: //R6.Root/R6.Release Sep 20 2023 17:15:31 (FINAL) Total memory: 11263770624 bytes "
"Engine/InitParams/InteropStartingPort@93#TID=0":"0"
"Engine/InitParams/RenderPreset@94#TID=0":"1"
"Engine/InitParams/QualityLevelName@95#TID=0":"None"
"Engine/InitParams/TextureQualityLevelName@96#TID=0":"High"
"Engine/InitParams/WatchdogTimeoutSecondsOverride@97#TID=0":"0"
"Engine/InitParams/ScriptsSilentCompilation@98#TID=0":"false"
"Engine/InitParams/ScriptsSilentValidation@99#TID=0":"false"
"Engine/InitParams/TweakDBSilentValidation@100#TID=0":"false"
"Engine/InitParams/PvdDumpToFile@101#TID=0":"false"
"Engine/InitParams/ProfilerEnabled@102#TID=0":"false"
"Engine/InitParams/ShowVersionWatermark@103#TID=0":"true"
"Engine/InitParams/WindowCaption@104#TID=0":""
"Engine/PC/SystemName@105#TID=0":"Windows 10 Home"
"Engine/PC/SystemVersion@106#TID=0":"10.0.19045"
"Engine/Scripts/PrimaryBlobModifiedDate@113#TID=0":"133093382739829761"
"Engine/Scripts/BlobPathUsed@114#TID=0":"Loaded"
"##CrashDump##/DumpCrashDataSeconds":"0"

Oh, trying verify/repair again still downloads 38 mbs every time. Weird. So I guess that wasn't part of the problem.

Tried to get it running on my system drive again. Wow there are a lot of people with error 0xC0000005 out there who never found any solution! seems bad! anyway I tried a bunch of fixes from every thread I could find for the last few years. no good. this game just cannot run on this drive.

This drive is an ADATA SX8200PNP. It's pretty good. No other problems with it. But I guess I'll keep running this game off of a busted old usb external drive instead