Just as a note here, and a request. We do not appear to have any Revit 2021 users having this issue at present, but if someone is, then please let us know.
Also, if those of you who are having this issue can provide detailed minimum steps taken in order to experience this issue, such as:
- Open the project from BIM360
- Click on that button
- Then I click on that other button
- Then it freezes
That would be a great help and much appreciated.