Hi Rainer,

Can you try a reinstall of SDL Trados Studio and make sure you do this as administrator?

• Open the Control Panel > All Control Panel Items > Programs and Features
• Select SDL Trados Studio - Remove products and features and click Uninstall.
• Download the SDL Trados Studio installer from your SDL account (if you don't have it already on your desktop)
• Temporarily disable your security software e.g. Antivirus or firewall application.
• Right-click the SDL Trados Studio installer and select Run as administrator.
• After The installation was successful notification, start Studio.

This may help as this error is often associated with a lack of rights.  If this doesn't help, and if running with your anti-virus disabled doesn't help then you should log a case.  For licensing or installation issues that prevent you from working we have a route for all customers to get help. This can be achieved really quickly using this link:

http://support.xl8.one/

Just fill in the form and submit it. If you can, use the Chrome browser to log the case, you'll get more success in completing the form, and make sure your email address is entered correctly or nobody will be able to get back in touch with you.