I am running Xcode 9.2 on 10.13.3 and just today ran into a problem with Xcode not recognizing Main.storyboard on an app that I am building. It worked on Friday and then today when I opened the app to work on it I get the following error:
.../Base.lproj/Main.storyboard: Interface Builder could not open the document Main.storyboard" because it does not exist.
Visually the file is there but does not respond. It is listed correctly in info.plist.
I tried pulling versions from Time Machine from last week and I still get the same error.
Is there anything short of rebuilding the storyboard that I can do to get Xcode to recognize it?
Did you try Removing the storyBoard and Re-Add it in Main Bundle ? Just make Copy of your Storyboard and Delete it from Xcode Project and Again Drag And drop the copy made in Xcode Project with check Copy items into destination group's folder (if needed)
And
Also check
Link - Interface Builder could not open the document ".storyboard" because it does not exist
Other options are Also Provided there