I encountered this issue on PC (windows app version)
I was playing ALONE
I was playing as Bruenor
I'm forced to play on console as a workaround
Steps:
I left the game running with my character at camp on PC while i logged in and played a couple rounds on console.

Result:
Game wont boot on PC anymore. Launches right into not responding.
If I force close the game, I receive a prompt to select either local or cloud save data. Neither selection works, the game still launches into not responding.

I tried deleting the local save file @ C:\Users\Bill\AppData\Local\CotH\Saved\SaveGames
The game still won't boot, I don't get the save file selection prompt anymore either.

I tried both windows app reset and repair options

I tried to completely uninstall and reinstall the game

Expected Result:
Boot the game on PC with cloud save data.