Bug Report OBS Causing BSOD Windows 10 (Undetected access violation resulting in Page fault)

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kokowang

Member
When using Video Capture Device source with a Logitech camera, OBS occasionally induce a page fault (ie - write to protected/restricted RAM locations, causing subsequent reads by the system to report unexpected values). Specifically OBS is somehow (not sure how...) incorrectly accessing lvuvc64.sys - Logitech's quickcam driver. I believe this is a backwards compatibility issue, as the webcam and associated drivers (latest for the webcam model) are ~6-10 years old (with minor updates for win10 support).
lvuvc64.sys is loaded as part of the Windows 10 Non-paged area (System reserved RAM), and OBS should not modify any contents of this file (directly or indirectly) in RAM. Any modification to the files loaded non-paged-memory will result in an immediate BSOD. Normally, attempts to modify such memory locations will result in an access violation and termination of OBS.exe if unhandled. Although an access violation is never detected, likely due to the ancient drivers being, for a lack of a better word, garbage.

-- The driver is functional and other streaming/recording softwares have no issues operating with these older drivers. I'm not exactly sure how OBS can either directly write induce a write to nonpaged memory, (considering it's not paged) but GCHD, Mirilis, Quicktime, and many other recording softwares do not have this issue.
-- Yes I've also tested that the ram isn't faulty. 25 passes, 0 errors.
 
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c3r1c3 said:
Where's the crash log?
Click to expand...
"The computer has rebooted from a bugcheck. The bugcheck was: 0x... (various locations)."
Would you like the memory dump file? (6GB)
Kernel: "The system has rebooted without cleanly shutting down first.... (continued useless information)"
Event data: none (all defaults. code 0. parameters all 0x0. etc...)
Bluescreen reports: "PAGE_FAULT_IN_NONPAGED_AREA" and the windows 10 super helpful frownie face instead of pasting useful information on a bluescreen.
 
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A page fault was detected due to incorrect handling of old Logitech camera drivers and the system froze in that state to avoid further data corruption. The system froze (blue-screened) in a state in which OBS was running. OBS never crashed and a crash report of the application was therefore never generated. The RAM dump file shows corruption of non-paged memory (kernel objects). Specifically, the memory blocks allotted for Logitech's webcam drivers is corrupted when OBS is running.
OBS spends over 30% of the CPU time modifying RAM when the camera is added to the scene while no transfer between disk and memory is occurring and usage is not affected by resolution & framerate changes (ie - it's not caused by buffers. No encoding is active at the time so all that's being generate). This excessive writing to RAM suggests that there is a bug causing random/useless modifications to memory, which is likely the cause of the corruption in the non-paged pool.
 
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Having the same issue. Also running Windows 10 with Logitech cameras . Two bluescreen crashes on loading OBS since updating from 18.0.2 to 19.0.2 today. One was definitely PAGE_FAULT_IN_NONPAGED_AREA citing lvuvc64.sys. The other I didn't note down. No crash reports available.

I have logs from the sessions causing the crash, and the previous one that launched fine if that helps?
 
This is an issue with the Logitech webcam driver. OBS cannot modify system RAM used by drivers, no program can - they can only talk with the drivers. The driver itself is causing memory corruption and thus the BSOD.

You may be able to work around this by changing the format / resolution / FPS of the camera, but the bug itself still remains in the driver.
 
I'm having this issue as well.
  • Windows 10 64-bit, current patching, no Creators Update yet
  • 2x Logitech C920, 2x Logitech C615
  • Bluescreen immediately upon launching OBS Studio 19
  • All cameras capturing at 720p
Here's the thing. OBS Classic works perfectly; all four cameras run just fine (including scenes with all four active).

While Logitech's crappy support and crappy five year old drivers are certainly a problem, something changed between OBS Classic and OBS Studio that's triggering this. Is there something that can be done to do whatever OBS Classic was doing that worked, some secret config-file magic, etc.?
 
isn't it possible for OSB to start cameras with an delay when starting the program? since last week I have a new C920 and an old C270 and together they are causing a BSOD with OBS. the first BSOD I have seen with Windows 10
 
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