The issue was that the multiframe editing toggle is a tool setting and not
stored in the object data anymore (which was changed in 4.3 so that users
don't have to toggle it in every object).
The batch caches of all Grease Pencils will include the multiframes even
when they are not active.
This leads to the issue that inactive objects don't rebuild their batch cache
when the setting is toggled and we access memory that is out of bounds.
To fix this (for now), toggling the multiframe setting tags all the Grease Pencil
IDs for an update. Obviously this is less than ideal, but the safest option as
of right now.
In the future, we should create a batch cache for each frame.
Then the render engine can request each frame when it's needed,
and we no longer need to tag all the objects for an update when
the setting changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/135636
785c9c9720