You need to delete all files in
%UserProfile%\AppData\LocalLow\Obsidian Entertainment\Pillars of Eternity\CurrentGame
%UserProfile%\AppData\Local\Temp
And most likely all stored files in
%USERPROFILE%\Saved Games\Pillars of Eternity (Except the save you want, but if the game has the same problem all over again, your save edit failed and the save is junk) So delete it, and quicksave out of an older save again.
If you still have saving problems, then I don't know
Not ALL data in Local\Temp
You should probably fix this before somebody actually does that.