Could not insert new outlet connection error

Question

I have created a custom cell for loading into a table. The interface is complete and now I am trying to link the xib and the class.

I have the split screen view open

Answer 1

I have the reported problem trying to add a new Watch target to an old project as I successfully did several times on blank projects following tutorials. I tried inserting the target an scheme and removing both the files, the targets and schemes, as well restarting Xcode and deleting the derived files many times. But each time I recreate the target and try to activate the Assistant Editor, it finds no correspondent file to the main storyboard, and if I manually select it and then try to drag a new outlet I get the error of the original poster. What else could it be? As a metter fo fact my error is quite different as you may see in the screenshot.