While attempting to carry out a V2V using VMware Converter I had a permissions related issue when selecting the source machine:
Permission to perform this operation was denied
I triple-checked my permissions within vCenter were sufficient to carry out a V2V, even temporarily granting my own account with the Administrator role directly to the location in question, but still received the above error.
I stumbled across this VMware Community posting which suggested that granting local Administrator rights to the account I was using on the Windows server where VMware Converter was running from might help.
For various reasons my account did not have local admin access to that server. I added my account to the local Administrators group and lo and behold taking that course of action worked and I could carry on with the V2V.
Note: Opening VMware Converter with Run as administrator rather than the above solution had not resolved the problem.