Hello,
My issue is that I can only see some of the classes defined in my project while searching in the Symbol Navigator. Many classes are not shown. Knowing that my Xcode project is big and I'm using cocoa-pods in it.
The issue occured in my iMac and MacBook.
Xcode version is 10.1.
The following solutions didn't solve my issue:
1. Restart Mac.
2. Restart Xcode.
3. Update Xcode to latest version.
4. Open the project in another Mac.