AttributeError: NoneType object has no attribute
The error "AttributeError: 'NoneType' object has no attribute..." probably means that you attempted to retrieve an object (such as a person, or family) by using its internal handle, but the database can't find it. Likely, the object is still there, but the internal database references have gotten corrupted.
To fix, first, make a Gramps XML backup.
Then, you need to run the menu -> Tools -> Family Tree Repair and run the tools:
- Check and Repair Database
- Rebuild Reference Maps
- Rebuild Secondary Indices
in that order.
If you still get the error after running the repair tools, then you should try creating a new family tree, and importing your backup. If still errors, try running the above tools on the re-imported tree.
If you still have issues, you may need to go back to an older backup.