Urgent Assistance Needed!!! - VMware converter 5.5 - error "An error occurred while opening a virtual disk. Verify that the Converter server and the running source machines have network access......."

Hi All

I have a need to migrate some VMs from a Co-located DC into a Shared farm I have.  Using VMware Converter 5.5, I get all the way to the end, and then get presented with the above error.

I have since looked at the VMware-converter-worker-5 log that was produced, but cannot see anything obvious in there.

Could someone please assist me urgently to have this resolved, as I am in urgent need of getting these VMs across due to their criticality.

Thanks in advance!