could not run the sketch (target VN failed to initialize)

hi there, I'm running windows 10, with an AMD radeon graphics card, latest version of processing. when running my sketch i get the error message "could not run the sketch (target VN failed to initialize)" and also a windows firewall notification, that it blocks some java functions. Again, if I allow access, I still get the error. This was a fully functioning sketch before. Any idea? Thanks