Won't activate after I put the activation code on SDL Trados 2017

Question

I have 2017 version SDL Trados and have been using it in recent months. Out of the clear blue sky, I couldn't continue using the program, because it wouldn't activate even after I followed an unexpected popped-up instruction. Following the instruction, I put the activation code in the blank, and an error message pops up, "activation failed. could not connect server address in the provider settings. The request was aborted, could not create SSL/TLS secure channel" in the Korean language (I'm using our local language Windows 11). 
 Please help me solve the probelm right away, because I have been wasting my time for the past few days while trying to find a solution to this unexpected problem!

Elisa Maxim · Answer

Hi Heewoo Kim 
 According to our system, your current license is Trados 2019. Trados 2017 will continue to work as long as it is installed on the same PC as Trados 2017, but we cannot guarantee its functioning long term. Once you processed the upgrade to Trados 2019, your license rights extend only upon Trados 2019. 
 Please let us know if you changed computers, made changes to your computer or changed the operating system, so that we can submit a case with the technical team for you. In this way you will be able to reactivate Trados 2019. 
 Kind regards, 
 Elisa

Trados Portfolio > 2. Licensing and Installation

Won't activate after I put the activation code on SDL Trados 2017