When installing Trados Studio 2021 SR1, I get the following error message:

Set-up did not complete. The error is:
Package 'SDL Trados Studio 2021 SR1' could not be installed.
Onherstelbare fout tijdens de installatie. Error number: 1603

Near the end of the installation proces, the installation is rolled back, after which I get the error message.

I've tried installing the SR1 package both from withing Studio and by manually downloading it from my account but the result stays the same. What makes it even worse, is that I can't use the previous Studio 2021 installation anymore. It just disappeared from my computer: start menu, program files, etc. it's gone. I noticed I didn't have the most recent Windows 10 Update (20H2) but even after installing that, nothing changed.

Any help would be very much appreciated.

Jeroen