Bluebeam® Revu® 2018.3 and above
While working in a Studio Session, a dialog appears, saying:
Please wait… A critical operation is taking longer than expected. This dialog will close when the operation completes.
Too much Session activity can overwhelm Revu. This dialog prevents user activity during heavy server loads to ensure all data is synced, so that no information is lost in the process. Once the actions performed by other Session attendees reach your machine, the dialog will disappear and you will be able to add markups.
All you need to do is wait for the server to complete the process; the dialog will close when all current activity is processed. If this dialog takes longer than 3-5 minutes to disappear, you can restart the application.