I had a similar problem with tableview images not appearing once I converted the storyboard file to be Xcode8 compatible. This looks like a bug with Xcode8, so until a bug fix is released, here is a work around:
- Open your storyboard in Xcode 8 and choose an initial device view. Make changes as you normally would.
- Once you have completed your changes, select the storyboard -> File Inspector -> Opens in -> Select ‘Xcode 7.x’.
- Select ‘Save and Close’ when prompted
- Your storyboard changes will be saved, and your storyboard will function as it did pre-Xcode8.
When you need to make other changes to the storyboard file, follow these steps again.