Multiplayer suddenly not working??

[NT2507]

So my partner and I have been playing on a multiplayer server they host everyday for almost 3 Weeks now, all Mods are updated and have been rechecked multiple times, no setting has been changed. When starting the server it only loads the chunks, afterwards it turned into a white screen followed by a complete blackscreen. My partner then decided to delete and reinstall the game which didnt make it work as well, we did play together yesterday even and everything seemed fine. I have been researching for the whole day now and no solution I had found worked.

 

When I tried to host my own server everything worked out fine until after Character Costumisation, the screen just turns black and thats it, No dialog or loading notification, pure blackness for over 10 Hours. 

It's really been frustrating is there anyway someone could help us with these problems?