Hi David,
There are a few things I’d ask you to check regarding this error, firstly can you review the first two FAQ here:
Specifically: “Security required for Bulk Edit usage” & “On-premises install: No projects are loaded and no error message is shown”
If neither of those solves your problem there may be further errors logged in the browser console, which can be accessed by pressing F12 in either IE or Chrome (or from the dev menu in other browsers). Can you open that console, and reload the app then copy past the complete error messages (if any) that you see there?
Thank you
Martin.