问题
On Xcode 9, all my storyboards seem to be displaying in blue outlines only. Doesn't seem to be a new feature....Anyone has the same issue?
回答1:
After a week of trying all the suggestions in the internet I found that Xcode 9 required some libraries in macOS High Sierra.
So install them and then it will work:
https://www.apple.com/lae/macos/high-sierra/
Hopefully it will help someone
回答2:
I has this issue in two different storyboards, where I can see an error on the top which said:
"An internal error occurred..."
In one of them I could solve the issue removing Derived Data following this steps on Xcode:
Preferences > Locations > Derived Data > click the arrow to open in Finder > Delete it
In the other one I wasn't able to solve it so I'm using Xcode 8 for that Storyboard (You can open both Xcode 8 and Xcode9b2 and code with them at the same time)
回答3:
This recommendation might helpful for others who are not able to solve this issue.
This issue could occur If Xcode debugging tools are not installed properly, While installing Xcode 9 from Mac OS 10.12.x. What I would recommend is you go to the below url, and install the additional tools(additional tools, comman line tools...) compatible with your OS version(v10.12 in this case).
https://developer.apple.com/download/more/
回答4:
i fixed this issue by Hiding Rectangles Bounds
goto Editor -> Canvas -> uncheck Show bounds Rectangles
NOTE: check/uncheck twice if not done on first try
回答5:
I had the exact same issue after upgrading to macOS High Sierra. Re-installing Xcode + command line tools did not help.
I changed this configuration in Xcode and it made the problem disappear: "Preferences" > "General" > "Locked Files" > "automatically unlock files".
回答6:
For me, I had both Xcode 8 and Xcode 9 open on same computer. Closing Xcode 8 and reopening Xcode 9 solved the problem.
来源：https://stackoverflow.com/questions/44532110/xcode-9-storyboards-are-not-displaying-properly