I’ve been trying to figure this out for very long (months) and thought that it is just a bug that will eventually be fixed in Blender 2.8, because it’s so clear bug that no one can go without seeing it. But now we already are in beta and it still is the case that I cannot edit the new object properties when one is added.
The settings are just grayed and I cannot add more segments etc to my objects.
Another thing is that the undo behavior is changed to something unusable. I cannot for example undo the modifier things I do, instead Blender is undoing something else and this basically destroys the project. I need the old undo behavior back which will register all the things I do in Blender. Not just some.
I believe that these 2 things are linked somehow, because I found from internet that the global undo setting (that is removed from user preferences?) will fix this. But the thing is that the setting is not there anymore where it was supposed to be. It used to be in “User preferences -> Editing” but not anymore.
How do I fix this?