I recently started using String Catalogs in my macOS app, Wunderbar. After adding the String Catalogs, I noticed that English was no longer listed as a supported language on the App Store. This was strange because English is the default language for my app and it should be listed as a supported language.

After some research, I found out that the issue was caused by not marking the keys in the Strings Catalog file for English as reviewed. This wasn’t obvious to me because I didn’t see any warnings or errors in Xcode. After marking the keys as reviewed by right-clicking on the key and selecting “Mark as Reviewed”, English was listed as a supported language on the App Store.

I hope this helps you too.