Gallery not loading after update

Since the update to 2.1 pro my gallery wont show up anymore :/ With Version 1.4.1 it worked fine, but now even a downgrade doesnt help to show up the Gallery again. I have already done several Resyncs and reinstalled the Plugin, but that didnt solved the problem too…
Can u please take a look at my Site?

https://www.sportkreisjugend-tuebingen.de/bildergalerie/

https://www.ads-software.com/plugins/srizon-facebook-album/