I am exactly at this part of the procedural foliage tool tutorial:
https://docs.unrealengine.com/latest/INT/Engine/OpenWorldTools/ProceduralFoliage/QuickStart/2/index.html
When I try to double click the spawner or foliage type actors by double clicking I get a blank window with no attributes to edit:
I did the grass tutorial before and had the same issue with the landscape grass type, somehow after a few tries it worked and a I finished the tutorial but now when I try to open the (still working) landscape grass type I get the same problem so I cannot change the attributes on it anymore.