Operating system: Ubuntu 20.10
Graphics card: Intel i915
Broken: 2.83.12 and 2.92.0
Short description of error
When using multiple Armature modifiers with Multi Modifier option Weight Paint mode doesn't work as expected, It doesn't paint vertices I click at and sometimes paints wrong vertices.
Exact steps for others to reproduce the error
Here is the blend file:
Steps to recreate it:
Create two armatures, place them to different poses, parent the default cube to one of then with automatic weights. Then add another Armature modifier, set it to the second armature and enable Multi Modifier. Add an empty vertex group and set it to the second armature modifier. Then when I try to paint this new vertex group it paints wrong vertices.