CA-2A free offer version 1 demo mode - offline registration not working

I installed SPlat 2016 12 and it seems to have reset some things.
When I now put the free offer CA-2A into the PC (the original version, not the current early version), I get the message that it's in demo mode (I'm sure I registered it when I got it)
 
Anyway, I created the offline registration file, put it on a thumb drive and now I am on my work PC and when I try submit the file I get the messasge
 
"An authorization response file could not be generated, if this error persists please contact Technical Support."
 
What could be wrong?