I think I narrowed it down, it happens when you paste lucid modifier as instanced AFTER it has already some recorded data simulated:
- Create a simple scene like a collision plane and two objects
- Assign one of the lucid properties to one of the object
- Run some simulation/test
- Copy lucid modifier and paste it as instanced on the second object
- Try to save: The error shows up.
So this is mostly a user error, although it would be better if it wasn't generating an error I suppose :) Trying to paste as instanced a modifer that already holds the recorded data of another object. If you simulate again and save, the error will not happen. If you do the previous steps without simulating before pasting as instanced, the error will not happen either.
Best regards