blender-errors-data

A Blender Python ReferenceError occurs because undo/redo operations invalidate cached bpy.data ID pointers. You must replace stored object pointers with name-based re-fetching using .get() to maintain stable references across state changes.

To avoid Blender crashes when mutating a CollectionProperty, never hold element references across add or remove operations. Use re-fetching or index-based access patterns instead of caching element pointers during collection reallocation.

In Blender 5.0+ Python scripting, delete RNA system properties using attribute access and property_unset rather than dict-like deletion. This prevents access errors when modifying system-level property definitions.

Blender crashes accessing freed StructRNA objects after remove mutations when you cache bpy.data pointers. Capture creation return values and avoid accessing references after remove operations to prevent invalid pointer dereferencing.

Caching bpy.data object references across Blender operators is unsafe because undo/redo and file load operations invalidate ID pointers. Store stable identifiers like names and re-fetch from bpy.data within each operator execution instead.

Debug stale Blender Python pointer issues by listing where your code caches bpy.data objects across operators and undo boundaries, then rewriting the access pattern to re-fetch safely by name using .get() instead of holding references.