Hello Nico,
Try starting the DB Studio from command line. Refer to the document below on how to start
Starting Database Studio - SAP Documentation
In addition I would recommend downloading the DB Studio 7.9 where we now have better error handling capabilities - I think the latest available is 7.9.8.14 in the service marketplace.
Database Studio 7.9.08 News - MaxDB - SCN Wiki
Regards,
Yashwanth