When the overview setting from CharacterA infests CharacterB on the same account(1), thereby destroying the overview settings CharacterB has made. The window settings do not also infest the wrong character. This not only completely destroys GUI layouts on top of destroying the Overview settings, it also leads to internal game errors where the windows semi lock up and fx can’t be dragged to move.
The combined errors can also freeze the client for over a minutes if trying to work with Overview while in combat.
(1): Same account means these errors can not be avoided using Launcher profiles.