Please include reproduction steps here!!!!
1. Override a prefab to your AF read-only directory, FuelStorage_S_US.et.
2. Right click the FuelStorage_S_US.et prefab in your addon, and press CTRL+SHIFT+U (Create/update Editable prefabs). An error will probably occur (see screenshot). Select Ignore All to continue. Say yes to run the scripts.
3. Navigate to the Editable addon, such as PrefabsEditable > Auto > Compositions > Slotted > SlotFlatSmall. There's no icon with an orange bar, instead it's a blank icon that I cannot open.
4. Removing these blank files causes Workbench to crash. See screenshots.