After setting up 20 IOSv images attached to unmanaged switches, I copied and pasted the configuration files for Full Scale Lab 1.
What I found was that each router would get to this point and then stop:
SETUP: new interface GigabitEthernet0/0 placed in "shutdown" state
SETUP: new interface GigabitEthernet0/1 placed in "shutdown" state
At this point, it would halt and go no further (please note I had not added a second connection for Gi0/2).
If I closed the console window and then reconnected, I would just get a blank screen.
I did, however, find that 3 of the 20 routers did load correctly (R2, R6, and R10).
It transpired that the issue was with the configuration line:
ip http secure-server
I changed this to:
no ip http secure-server
Now all of the routers load just fine.
Just thought I'd post this in case anyone else had run into a similar issue. :-)