Lightroom does not connect to CC

[tobiasjoest]

Lightroom 4.0

Macbook Pro

When I start Lightroom, the photos, folders and albums do not show up. It works maybe 1 out of 10 times. The other times it doesn't work. I tried signing out and log in again. Nothing. Close Lightroom and start it again. Nothing. Use different internet connections. Nothing. I have to work with this so I can't spend time to figure this out. This morning I am already trying to use Lightroom for more than 2 hours. 

This is a big pain.

Does anyone have an idea what this could be?

Thanks

Tobias