It will never login and all I get is this: The server is working for your request... please wait! Ihre Anfrage wurde bereits aufgenommen... Wir bitten um etwas Geduld!
The message "The server is working for your request... please wait!" using MAGIX Service Center appears if you already submitted a form and clicked submit button again (e.g. if you double click the button or pressing Enter more than once). If you're doing nothing like this but using a password manager (which and which Browser?) maybe its plugin is the reason.
If this message appears there is no reason to worry, just click the OK button and the next page (after) login should appear if email + password was correct.
If there is some trouble with a password manager or other browser plugin try to use a different browser or inkognito mode without plugins. Maybe also your stored password is not correct; the account credentials are the same you are using here.