On both Xcode 4.4 and 4.4.1 I'm experiencing the same issue in that with the specific project I'm working on, I don't seem to be able to rename any classes or variables from the Refactor menu option.
Each time I try and do a rename, I type in the new name for the class/variable and click Preview at which point the bottom left begins a spinner with Finding files.... However, I then get a message saying:
The selection is not a type that can be renamed.
Make a different selection and try again.
I'm pretty sure that this is not an issue with my specific install of Xcode, because I can refactor other projects fine, it's just that I can't seem to be able to refactor this specific project.
Anyone with any ideas? I don't have any particularly exotic configuration for this project, it just seems to be a random affliction. I've deleted all of my derived data and re-indexed, but that doesn't seem to help.
Since it works OK in other projects, I'm thinking one thing I could try to do is re-generate the actual project file(s) itself. I don't know if there is a way to do this automatically?
I have managed to solve this issue after trying many different things (tweaking project settings, pch, etc.) and it turns out there was a very simple (and totally counter-intuitive) method of fixing this issue.
All I have done is:-
Project to Project Copy).Project (the original folder) to trash.Project Copy to Project.Mysteriously, everything now works fine.
I really cannot figure out why this works. As mentioned previously, I had already deleted all derived data, etc. so I don't know why this should make things spontaneously work, but it does.
Would appreciate anyone who is able to shed some light on this as it does expose just how fiddly Xcode can be, and any understanding of what goes on under the hood is always beneficial.