Plugin loaded from UNC path crashes when loading USD file containing MaterialX (MaterialXGenShaderMayaUSD.dll)

[pzloty]

Describe the bug
With Maya-USD plugin located on UNC path (e.g. shared storage) on Windows 10) Maya crashes with C0000005: ACCESS_VIOLATION for ...\USD\bin\MaterialXGenShaderMayaUSD.dll when loading USD file with MaterialX material.

Steps to reproduce

1. Load Maya-USD plugin from UNC path. To reproduce locally use e.g. //localhost/c$/tmp/usd/2025/0.29.0/...
2. Maya usd.mod file paths.

   + MAYAVERSION:2025 USD 0.23.11 //localhost/c$/tmp/usd/2025/0.29.0/USD
   + MAYAVERSION:2025 MayaUSD_LIB 0.29.0 //localhost/c$/tmp/usd/2025/0.29.0/MayaUSD
   + MAYAVERSION:2025 MayaUSD 0.29.0 //localhost/c$/tmp/usd/2025/0.29.0/MayaUSD/plugin/adsk
   + MAYAVERSION:2025 MAYAHYDRA 0.6.2 //localhost/c$/tmp/usd/2025/0.29.0/MayaUSD
   

   (content is same as the one from installation, only paths are modified).
3. In Maya, load maya-usd and lookdevx plugins:

   loadPlugin mayaUsdPlugin;
   loadPlugin LookdevXMaya;
   

4. Open USD Layer Editor, Create -> Stage From File...
5. Select a chess_set.usda (from https://github.com/usd-wg/assets/tree/main/full_assets/OpenChessSet) and confirm
6. Crash

Expected behavior
Load a file without crashing when plugin is on UNC path.

Attachments
MayaCrashLog240816.1553.log
MayaCrashLog240816.1553.dmp
scene.ma.zip

Specs (if applicable):
Windows 10
Maya 2025.2
USD 0.29.0_202406120710-f8eb6c1 (pre-compiled from git releases)

Additional context
Used OCIO config is this one: https://github.com/colour-science/OpenColorIO-Configs/blob/master/aces_1.1/config.ocio
To clone chess asset:

git clone --no-checkout --depth=1 https://github.com/usd-wg/assets.git
cd assets\
git sparse-checkout init
git sparse-checkout set full_assets/OpenChessSet
git checkout main

[wallworm]

Thank you for reporting. We will look into this.