Why does my Sattcon 35 CU45 not start

I have a Sattcon35 plc and it won't go into run.
I only have power supply, CU45 and SICB panel.
I am able to login to the PLC and send a program, but when I try to start the PLC it stays in stop.
Is there any way I can see why the PLC won't go to start?
I tried with a program which runs in the factory on another PLC and I also tried with an empty program (just 1 PM which only has the BEGIN statement).