I posted a question about the message last January, but I finally realized that I couldn't get a notification for the support mail due to an error in the mail site and there was an answer.
I think I even deleted the answer by mistake because I'm not good at manipulating the site here. I'm so sorry.

My problem in January has not been solved yet, and other colleagues are not able to use the deactivation function because of the same message.
My colleague has not deactivated it since the first activation, but he is experiencing the same phenomenon. I hope you can solve it as soon as possible.
I won't miss the mail this time! I'd really appreciate your help.

My colleagues and I both use SDL Trados Studio 2019.