I had the same problem as described in this topic:
https://forums.obsidian.net/topic/106105-cant-load-from-title-screen-after-hotfix/
I fixed this by looking at the output_log file. It seems like my "CurrentGame" Folder seemed to be corrupt and not accessible/writeable anymore (C:\Users\X\AppData\LocalLow\Obsidian Entertainment\Pillars of Eternity II/CurrentGame). I don't know for what this folder is good for but it seems to be playing an important part in running the game. Deleting the folder was not possible so i ran good old checkdisk and upon rebooting I was then able to delete the CurrentGame Folder, which fixed all my issues.