I am having an extremely frustrating issue with XCode 7.3 (however, this issue has persisted since I installed XCode 7.2) and Swift code, and I am hoping others have had thi
I have the same problem. But finally solved it. I make two change, not sure which is the key point but you can try them all.
Within the same folder as your project's Derived Data is a Module Cache. When Code Completion stopped working, deleting this fixed it.
Close Xcode and delete the ~/Library/Developer/Xcode/DerivedData/ModuleCache directory.
Go to the Build Settings of your target, then search Enable Modules
If it's Yes, change it to No, and you may get some build error, just change it back to Yes.
After two steps above you should Clean(Shift+Command+K) your project.
For now you may fixed the problem.