Trouble opening Groupshare project due to "The requested operation cannot be performed on a file with a user-mapped section open"

When I try to open a Groupshare project which has been assigned to me, the process stops and the error message "The requested operation cannot be performed on a file with a user-mapped section open" is shown.

I have tried:

- restarting Studio

- restarting the computer

- resetting the server connection as per https://gateway.rws.com/csm?id=kb_article_view&sysparm_article=KB0037451 (however from what I have understood so far, this could potentially be unrelated to the server connection)

Running Studio 2021 on Windows 10

Fast help much appreciated

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