First comes the error message: There was a problem loading resources from the server Please try again when you try again you get into the server/multiplayer world and all or some content is pink or not visible (this problem occurs on every server and On the multiplayer worlds, this problem also occurs several times and is extremely annoying) The problem sometimes corrects itself and starts again in a few days or hours 

How to reproduce it:

1. Click Play then go to Servers or Friends
2. Enter your friend's server or world Important: Your friend's world must have an addon installed and applied to the world 

This problem is probably only happening to me