When I run Session Browser in Toad Beta 184.108.40.206 I receive a box with error message “The user does not have permission to perform this action.”
Then no data is shown in Session Browser.
But when I run Activity Monitor in Microsoft SQL Server Management Studio 2012 it works (the same user, the same database).
I do not have system administrator role, so my permissions are limited.
Here is a screenshot from Microsoft SQL Server Management Studio: