When there are more than 20 projects, if you go to Admin > Projects and go to page 2 or any page other than the first page of projects
This is how to reproduce:
1. Add enough projects to trigger pagination (use the command line 'keystone --os-username admin --os-password ???? --os-auth-url http://localhost:5000/v2.0 --os-tenant-name admin tenant-create --name=proj##')
2. Go to Admin > Projects
3. Click on "More »" at the bottom of Projects table (or click more times to go to any subsequent page)
4. Now you should be on a Poject page other than the first.
5. Try removing any project (one or multiple at the same time)
6. At the prompt click on "Delete Project(s)"
you'll notice that the confirmation balloon doesn't show, and if you go back to the same Projects page you'll see the project(s) you tried to delete is (are) still there.
Did a bit of investigation, looks like this is a pervasive problem across all paginated actions, not just on the projects panel.