I've just applied the last 5 security patches to a client's site and now some of their 3rd party modules are misbehaving in the admin dashboard. I've fixed most of them but 2 in particular are vexing me. Magestore PDF Invoice Plus and FME Percentage Pricing When I click on the "Manage Templates" link (for PDF Plus) and "Manage Rules" (for Percentage Pricing) in the menu I get a screen with no content. The header, menu and footer are loading, there's no PHP errors and there's no grid.
The customer's support period has run out and he doesn't want to buy the extensions again. Any ideas on how to fix the blank grids?