Transporter: creating new VM from Windows Transporter file hangs, "Preparing to Transfer"

After trying for an hour and failing to get Transporter from Windows talking to Transporter/Importer on Mac, I gave up and transferred as a file, using Windows Transporter to write a .pvm, ~117GB and copied that file to my Mac desktop. However, trying to import this PVM into a new VM on Mac, the Installation Assistant is completely hung, at "Transferring your PC", "Preparing to transfer...". The progress bar has not even started. It has, however created a the 74GB PVM in my ~/Parallels folder, which is the size that it said it would be at the start.

Now what? This is a pretty important feature to me, as the org I'm working for is all Windows based, so slurping up their IT-approved Windows image is critical to using enterprise apps etc.

 

Found the problem - I had just installed the trial (waiting for purchasing to deliver my license) and wasn't logged in, apparently. Once I quit the process and logged in, started the trial, it's now merrily important.

THIS IS A NASTY USER TRAP!! All my wasted time could have easily been prevented, had the trial version prompt for login to start the trial on first launch, rather than *appearing* to be running normally, with things silently failing / hanging. Please fix - not for me, but the next person!