Assistant admin suddenly can't access the Bulk User Management screen?

Maureen.Barrow4

My assistant admin suddenly can't access the Bulk User Management screen. He can see the Bulk User Management tab, but when he clicks it, he gets the error message below.

 

Any guesses on how we can fix it? We haven't changed his permissions since last week. I (the main admin) can access the tool, but when I impersonate him, I also get the same error.

 

In the Users tool, he has at least the following checkboxes selected:

• Create a User in the Database
• See the User Management tool
• Import Users from this Organization