I had this error since yesterday and couldn’t figure out what was causing this.
Tl:dr – Check your Resources folder in your project folder and make sure you don’t have copies. Then add them properly into your workspace in XCode.
The detailed version:
My initial thoughts was my Bundle name, identifier and product name were different but changing either wouldn’t work. But then I ran into this thread:
Update: Xcode doesn’t like it when you have a referenced directory called ‘Resources’ within your resource bundle.. but instead of complaining about this, you end up wasting half the day trying to resolve all the other issues that it throws up at you instead (see previous two posts).
All is now resolved and working as it should.
Looking at my work tree I had 2 Resources folders. One under my project folder and another inside my proj.ios_mac folder. Not only that I had the contents of my Resources folder copied within proj.ios_mac!
Deleting these copies, selecting “Add files to [project]” eventually did the trick.