You can get around this by doing everything you need to do in those stats, saving, then going to the mod folder, and opening your Object/Potion/etc .txt document and manually modifying the root template in there to what it should be.
I did that and it worked for adding the Demon/Djinn/Frog form to my Druid class mod - after this started happening!
Do not edit the .txt files. Edit the .stats files. The .txt files are generated data; the editor does not read .txt files. The .stats files can be found in
Data\Editor\Mods\<your_mod>\Stats. Once you make a change to the relevant .stats files, you will need to
reload stats from the main menu/toolbar, and then make a temporary change to the tables you want to save so the Save button will activate. When you save, the editor will regenerate the .txt files. The workaround steps are simple:
1. Edit the .stats file.
2. Close the Stats Editor, if open, and reload stats.
3. Reload the table in the Stats Editor.
4. Make any change.
5. Click the Save button.
6. Revert that change.
7. Click the Save button again.
