Custom Sidebars not showing options / choices

Howdy.

I've installed custom sidebars pro and want it to only show up on a certain category of post

However, when I click on the "Sidebar locations" under the sidebar, this opens the "define where you want the side bar to show" screen, for a splitsecond you can see all the options to tick, then these all dissapear and I am left with the top bar of that area and no where to tick.

Is there an issue I should fix in config or anything?