Ok, so I started having this problem as well right after patch 5.35. Not only am I getting this error in-game, my gear sets, macros, and hot bars were not saving either. Every time I log on, I have to re-equip and fix my hot bars and basically gave up on macros completely.

Things I have tried:
  • uninstall/reinstall the game
  • run game as administrator
  • pause onedrive (though my onedrive never sync with my doc folder so not sure what this has to do with it)
  • go through every gearset hot bars to make sure i got rid of all removed skills from past patches
  • check to make sure my doc folder is not read-only. I also did realize some items will keep revert back to read-only on its own. I have tried running command prompt using attric -r +s command (access denied). So not sure what else to do here.

Ok, after having done all that, the error/problem continues. I continue to start game each time as admin. About a week later, it stopped on it's own and everything's back to normal. 2 days ago, after the maintenance, it started again out of NO WHERE. I have now once again tried to go through all those steps. Nothing works. I am desperate and Square Enix support is no help at all, takes like a week for them to answer and gave me useless tips like reinstall the game which i already told them i've tried.

Please, if anyone have any other suggestions, I would appreciate it.