I had that problem too and I had to reinstall FH but found out that wasn't necessary. Turns out there was a particle file with _0 at the end in the my_objects folder. Check other folders to see if there are any other ones. And you might have to install FH again. To do that:
1. Copy Exports/Media/Presets/My_presets/Screenshots folders, copy the Items.cfg, emotes.cfg, markings.cfg and music.cfg (if you have custom music) and paste them into another folder.
2. Uninstall FH.
3. After uninstalling, delete the FH folder.
4. Download and install FH again.
5. Move the copied folders + files back into the FH main directory and let everything overwrite. Now you won't lose your custom files.
Hopefully this will work if nothing else does