Acronis gets stuck during backup - NOT Working AT ALL !

Hi,
my Acronis is not doing nothing.
I have set that my whole C-Drive shall be backuped to my external USB-drive and the task starts, but never ends. Acronis remains in the starting phase for hours until I try to canel the process. Not even that is working.
What am I doing wrong???

I am using the complete same setup on my laptop and there its working just fine.

HELP !!! THANKS !