Oh my god! I got it! Shame on you german_market_ready and Flagbit!!
Ok first i upgraded all extensions again with
./mage upgrade-all --force
Then i got the error
because Flagbit upgraded to an incompatible (?) version.
class ‘Xml_RecommendationAdapter’ not found
The class is called from Flagbit_Flagfinder so i tried to uninstall the extension (since i can not use it in germany anyway).
When trying to uninstall with Magento Connect i got the Error that i can’t uninstall it because it is requiered by community/market_ready_germany 2.1.40
WHY THE F*** is Flagbit Flagfinder requiered by market_ready_germany if i can’t use it in germany anyway?!?
Finally i got my up and crossell products up and running again after i did run the following from the command line:
./mage uninstall community Flagbit_Factfinder --force
So --force is my new sudo :D