Why can't I browse type for an workflow activity variable?

Question

I am working on a WPF app that contains a rehosted workflow designer.

When I add a new variable I can not select a custom Variable Type. When I click on "Browse for Types..." nothing happens:

Same is for "Array of [T]". The targeted .Net version si 4.5.1. What could be the issue?

Answer 1

So, the question was kind of specific to my case but I will answer it anyway and maybe it will help someone.

The problem was that I was using MahApps Metro style. If I remove the style applied to the combobox it then works. You could do it like this:

myGrid.Resources.Add(typeof(ComboBox), new Style() { TargetType = typeof(ComboBox) })

Answer 2

The "imports" tab on the bottom may need to have the namespace of the type you wish to use. Fill that in and then you should be able to browse for it.