If you are getting error that the reddarkedge.png is not found then use the following steps to remove the file from your project.
In xCode “Supporting Files” folder if you see that reddarkedge.png in red then you need to hard delete it. Even if it is not in red then hard delete it using Control + Delete or Command + Delete. Once they are deleted also make sure they are not in the Copy Bundle Resources. Click on your xCode project. Click on Build Phases. Click on Copy Bundle Resources. If you see the reddarkedge.png file in there hard delete it.