Can't connect IBAction in Xcode

Question

When I drag from a button on the storyboard to my view controller Swift file, I only get the option to insert an Outlet or Outlet Collection.

Similarly, if I create the

Answer 1

My solution was to delete the UIButton from the .xib file and to add it again. Looks like something strange is happening in the .xib file, readding it should be a quick fix.