Read this thread https://discussions.apple.com/thread/4789691?tstart=0
This fixed the issue for me:
sudo /usr/libexec/PlistBuddy -c "Delete :JavaWebComponentVersionMinimum" /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/XProtect.meta. plist
In the comments to the linked article someone suggests to comment out the node in stead of deleting it. Probably safer (it's explained further down how to do that). Anyway I already spent to much time on this nonsense, deleted it and it worked, so I'm happy.