Windows 10

PrintMusic 2014a v855

Needed to replace my computer, so I followed instructions for deauthorizing PrintMusic.  On new computer, I re-authorized on Aug. 13th, and all was well.  On Sep. 13th, PrintMusic wanted re-authorization.  I went through the Authorize screens, and got an error "...please check your serial number and email address and ensure there are no spaces...".  I went online to my account, and it showed the new "computer ID" properly (1 seat used, 0 seats available).  So I deleted this authorization, thinking I could start over.  I go through the pre-populated Authorize screens, and get the same error message every time.

As a test, my brother installed PrintMusic on his machine, and used my serial number and email, and it Authorized perfectly.  It showed up properly in my online account.  He de-authorized immediately.  It disappeared from my online account.  So there is no server issue.

I've tried completely uninstalling and trying to delete all traces of PrintMusic from my system, then re-installing.  The Authorize screens are still pre-populated with my serial number, email address, etc., and it still fails. 

I've also tried creating a new local Windows user and installing while signed on with the new user.  Still no go.  I've tried installing a trial copy of Finale thinking it might help (can't authorize it, of course).  PrintMusic still errors out. 

I've read that the authorization process needs ports 80 and 443 to be open--are there any special antiviral software settings or router settings that I need to deploy?

Any suggestions for purging/resetting PrintMusic on my computer such that it will re-authorize correctly?  Or is this something that Support must handle?