Xcode 8 hangs / unresponsive when opening storyboard

Question

I\'ve recently upgraded to Xcode 8 and updated my project to Swift 3. All worked fine for a little while. Storyboard loading has always been slow (even when still running Xcode

Answer 1

In my experience, for an old project, opening with XCode8, it urgently wants to ask you some question about default device to view storyboard with. This question is so critical that until you answer it, you are staring at an invisible dialog window until XCode becomes unresponsive.

A couple solutions worked for me:

1. If you get a 1.5 second window of responsiveness when starting XCode - immediately switch to a non-storyboard file. If working with a split pane editor with the storyboard in auxilary panel, toggle it off.
2. Create another storyboard, open it, XCode will ask you the question about default device.
3. Answer the question, save the project state and hope to open the storyboard

Deleting these capabilities allowed me to re-open the storyboard