The issue you have is a known issue for
Trados Studio CU8 that is covered in this
Cumulative Updates for Trados Studio 2021 article: In this release, it is not possible to open
WorldServer packages through a double-click in
Windows Explorer. We will address this issue in the next update.
To open
WorldServer packages, use the Open
WorldServer Package button in
Projects view with the
WorldServer app installed.