After saving a requisition template that has got existing requisitions, you cannot enter the configuration screen for that requisition template again, until you manually reload the screen or leave it and come back again. If you try to do so, you get Internal Application Error message.
Go to configure requisition template for a template that has got at least one requisition created with it
Change anything (eg. show or hide any column)
Click "Configure" at the same template again
When a requisition template has any templates assigned, a save creates a new instance of the template in the database. The UI queries for the old ID though and fails.