Configure SLD - Browserwindow stays empty

Hello,

I copied a solution manager system to another server to be a sandbox for Solman Upgrade.

In old existing system I can open http://localhost:50000/sld and can login into SLD.

In new copied system I get an emtpy browserwindow with URL:

http://localhost:50000/webdynpro/dispatcher/sap.com/tc~sld~wd~main/Main

What do I have to do that SLD is shown?

Regards,

Julia