New Windows install, multiple Blender versions crash: EXCEPTION_ACCESS_VIOLATION (Python 3.12.0 conflict?) #115648

New Issue

Nazo · 2023-12-01T07:42:25+01:00

Nazo commented

2023-12-01 07:42:25 +01:00

System Information
Operating system: Windows 10 Professional 22H2
Graphics card: nVidia Geforce RTX 3060Ti (8GB)

Short description of error
Shortest description: as long as the PYTHONPATH variable is set it crashes instantly on start with EXCEPTION_ACCESS_VIOLATION Unsetting it allows it to start (but breaks other things using the installed Python.)

Long version: I recently reinstalled Windows to resolve some unrelated issues. This is the same version of Windows, but of course I reinstalled all sorts of things including Python (3.12.0 was current at the time I downloaded it.) That also includes the latest graphics drivers (though as it turns out that is unrelated.) I originally tried Blender 3.1.0 as that's just what I had handy (I kept it portable,) then I updated to the latest, but it still crashed. I also tried an install though I prefer to keep it portable and that didn't work either. As per the other recent threads with the same error message I tried one of the dev builds and the resource candidate, but they all crashed too. However, I noticed the .cmd files to try various debug options and tried them. They all worked. I got suspicious and looked at the files. They all start with SET PYTHONPATH= to clear the Python variable. As it turns out that is the only thing required to make it start -- no other debug mitigations needed. If I open a terminal there, clear PYTHONPATH, and then run Blender it just works without a crash. I also tried it with a portable Python 3.10 (not venv) configuration and that worked too without clearing the variable (the portable Python has its own PYTHONPATH variable pointing to its own binaries and scripts.)

I don't know if it might be some sort of conflict with Python 3.12.0 or something else, but regardless, clearing PYTHONHOME before starting Blender (or using a portable Python 3.10) works every time.

Exact steps for others to reproduce the error
Presumably install Python 3.12.0 and then run this.

**System Information** Operating system: Windows 10 Professional 22H2 Graphics card: nVidia Geforce RTX 3060Ti (8GB) **Short description of error** Shortest description: as long as the PYTHONPATH variable is set it crashes instantly on start with EXCEPTION_ACCESS_VIOLATION Unsetting it allows it to start (but breaks other things using the installed Python.) Long version: I recently reinstalled Windows to resolve some unrelated issues. This is the same version of Windows, but of course I reinstalled all sorts of things including Python (3.12.0 was current at the time I downloaded it.) That also includes the latest graphics drivers (though as it turns out that is unrelated.) I originally tried Blender 3.1.0 as that's just what I had handy (I kept it portable,) then I updated to the latest, but it still crashed. I also tried an install though I prefer to keep it portable and that didn't work either. As per the other recent threads with the same error message I tried one of the dev builds and the resource candidate, but they all crashed too. However, I noticed the .cmd files to try various debug options and tried them. They all worked. I got suspicious and looked at the files. They all start with SET PYTHONPATH= to clear the Python variable. As it turns out that is the only thing required to make it start -- no other debug mitigations needed. If I open a terminal there, clear PYTHONPATH, and then run Blender it just works without a crash. I also tried it with a portable Python 3.10 (not venv) configuration and that worked too without clearing the variable (the portable Python has its own PYTHONPATH variable pointing to its own binaries and scripts.) I don't know if it might be some sort of conflict with Python 3.12.0 or something else, but regardless, clearing PYTHONHOME before starting Blender (or using a portable Python 3.10) works every time. **Exact steps for others to reproduce the error** Presumably install Python 3.12.0 and then run this.

blender.crash.txt

19 KiB

blender_debug_output.txt

65 B

blender_system_info.txt

21 KiB

Nazo added the