Trouble Communicating With Server - Linux Mint 20.04

Hi all,

Trying to register the latest download of Neck Diagrams on my Linux Mint 20.04 desktop running the latest Wine. Tried the various Windows versions: 7, 8, 8.1, 10 under Wine but that didn't help.

It will take my ND1 Code, but when pasting in ND2 my upgrade code, it pops up an error "Trouble Communicating With Server".

Also tried pasting ND2 code first, it took it, but got the same error when pasting the ND1 code.

I am not running a firewall or any anti-virus software.

Is there a way to manually enter the registration codes in a config file?

Thanks for any ideas!

Phil