The application bundle does not contain a valid identifier

I solve this problem after I delete all build files by Xcode. Your build file path at Xcode > Preferences > Locations > Derived Data

If you didn't change the default path, Your path is like

I just deleted all files under DerivedData

In my case, this problem occurred when I manually removed a pod from my file browser in XCode. In order to fix it, I deleted the associated entry in my podfile, and ran 'pod install' from the terminal. Additionally, I had to delete the relevant search paths and other references to that pod. And of course I had to clean the project.

In my case, my app's bundle contained a dash like com.some-thing.app so I just changed it to com.something.app and the problem was fixed.