Current content BuildID: 3847951
(Not sure if that is the right number, just the number I found in Steam. There is no number in the top right of the menu)
Wait, in the help menu of the TW launcher i found Version 3.21.4
While playing a multiplayer campaign match with my friend, after several turns I zoomed out and zoomed in while it was his turn and when he ended his turn my screen blanked. The user interface is still visible and works. I was able to use the interface to select between my settlements, build, reinforce and do everything normal. I just can't see anything. The map and generals are just one giant brown blur basically.
We tried restarting our games and rejoining, did not work.
The only thing I can think of in hindsight was making sure he had auto-save turned on so we could load the turn previous and see if it fixes it, or cause it to trigger again.
I will be posting a screen shot of what it looks like once my friend gets back on later. (I know my description sucks, just wanted to get it known ASAP)
I can not add the save file as the file format is not supported.