Player activity screen stays blanc

When I go into my realm's player activity screen, it won't load anything. It worked a while a ago, and now since a few weeks it seems like it doesn't anymore.

Even after waiting for a few minutes, the screen stays that way.

I currently have 94 people invited to my realm.

Realms Owner is Plagiatus

EDIT:
Turns out it's working on a different PC other than my main one. I'll try to get the system surroundings afaik.