I have used tags in my database to differentiate different branches of my family tree. Somehow I now have a duplicate of each tag in the 'organise tags' list. Only one of each shows when I click on the 'tagged selected rows' icon in the person view. But if I choose 'edit the tag list' in the person editor the duplicates show, with only one of the duplicates ticked. In the person filter editor, the duplicates also show. I have tried exporting and importing into a new family tree but that doesn't help. How can I get rid of the duplicates without risking removing the wrong one and losing a tag that could be on a few thousand people?