New to forum so hope this is posted in right place.

I am having trouble setting up a Virtual Lab in Backup & Replication 5.0
When going through the Lab wizard at Network section, when I choose Basic (automatic configuration) then next, I receive the following error

unable to automatically choose masquerade network address for non-private network address 192.128.0.0
Production network name: 'Production Network'
I realise the range in this production range (not a real production network) is not within the private range but is there any way round this problem without changing the production network range? I have checked into Advanced (manual configuration) but a little unsure on what to select and worried I affect the production network.
Any assistance would be greatly appreciated.
Thanks