Registration Key no longer working

[G0zer]

I have been prompted to enter my key again (App version is too old). I have it saved so I paste it into the box but it will not accept it. Any thoughts? Yes this is a purchased key.

Thank you

[Billycar11]

make sure there is no spaces before or after the key and make sure to copy it as plain text might need to paste it some where as that first.
if none of that works email the developer with the email address you bought it with and maybe the key ask on that one.

[G0zer]

Thanks but that didn't work. deleted v 1.17.3 and downloaded the updated v1.17.4. same issue, frustrating.