New Post: stuck at "Running Prerequisites Installer (offline mode)..." on Windows Server 2012

I'm doing an offline/remot install on a single Server SP2013 farm. During the step:
"Running Prerequisites Installer (offline mode)..."
the Installation does not continue. I have to cancel the Installation and re-start it and then it does increment the "." and the Installation of the prerequisites finishes sucessfully.

Any tips on how to fix that?
thanks