there is a bug in 16.5 radial menu UV layout tool. I used UV with radial menu and if you choose UV layout it does not work correctly, you have limited options and you cant manipulate with handles. if you add it with TAB then it works just fine. I will fill out bug report.

Varomix found this during his Lamp Tutorial.

the solution from Varomix is to edit the UV radial menu layout tools command by adding ::2.0 to end of it.