An asterisk means that a change has been made to the document, and it hasn't been saved yet. I'm 90% sure I know why it's doing this, but I'm not sure how to fix it. I'm guessing that at some point in time you got the attached message about automatically deleting untitled viewports and checked the box and clicked yes. Now every time you open a file with untitled viewport (common in CAD files) it automatically deletes them which it recognizes as a change to the document that needs to be saved. The problem is that I can't find any setting that lets you undo this selection.
My suggestion would be backing up your settings, resetting to default, and then reloading your settings to see if this works.
To backup and reset your settings, within Administrator:
- Search your PC for Bluebeam Administrator
- Close Revu if it is open and leave the Administrator up.
- Click the Revu tab.
- Click the "Backup Settings" button.
- Save the file to a location of your choice.
- Now click the "Reset Settings" button.
- Click "Yes" when prompted and click "OK".
- Relaunch Revu and see if the behavior has changed.