3DExperience Launcher cannot be started

Hello,
I recently had some problems with logging in and connecting to Solidworks, so I completely uninstalled and reinstalled the 3DEXPERIENCE Launcher once. But now I have the problem that I can no longer connect the local application to my account. Each time I am prompted to reinstall the application or else enter the new port number. But when I enter it, I get a message that it is not available. Can anyone tell me how to fix this problem?