Groupshare package cannot be opened

I received a Groupshare package that I cannot open. It may be that the LSP made some error in constructing the package.

I could download the package from the Groupshare-server, but then could not open it for translation.

The following things look strange to me:

First, in the Groupshare notification, the Assigned users field shows No permission to view this list

Then, when I try to open the package in Studio 2017, and open the File assignment layout in the Files view, I get all fields (preparation, Translation etc assigned to Anonymous user and I cannot open the file for translation (greyed out).

What is wrong here?