Hello Berthold Kynast ,

We have an informative Wiki Article here which explains the procedure of having both 2019 and 2021 installed and active side by side on the same machine.

https://community.sdl.com/product-groups/translationproductivity/w/customer-experience/3183/03-2-installing-and-activating-studio-2021-and-studio-2019-side-by-side-upgrades-only

As you have upgraded from 2019 to 2021- there is no longer a separate activation code for 2019. When you activate 2021- this will also activate 2019 as long as both versions are on the same PC.

Thanks for the link. Yes, this I thought as well, but it did not. or maybe it was a mistake to install first 2021 without activating it, then install 2019, and only then activating 2021?

Hello Berthold Kynast ,

Please deactivate Trados 2021 then remove it from your system (Control Panel- All Programs )

Now install the latest version of 2019 from your RWS account (you won't be able to activate it at this stage)

And then reinstall Studio 2021 and activate.

Through the activation of Trados 2021- 2019 should now also run.

Hope this helps.