.app does not have an executable path after installing over an old build

Question

I have a TestFlight build that one user has downloaded, then we released a new version and they installed over that build. They got this error when trying to launch the app:

Answer 1

From "Core Foundation Keys": "CFBundleShortVersionString (String - iOS, Mac OS X) specifies the release version number of the bundle, which identifies a released iteration of the application. The release version number is a string comprised of three period-separated integers. The first integer represents major revisions to the application, such as revisions that implement new features or major changes. The second integer denotes revisions that implement less prominent features. The third integer represents maintenance releases. The value for this key differs from the value for “CFBundleVersion,” which identifies an iteration (released or unreleased) of the application. This key can be localized by including it in your InfoPlist.strings files."

CFBundleShortVersionString also mustn't contain any letters, only integers are allowed. So if you have something like 1.2.5b1 the app won't start, strangely with an error like "...does not have an executable path...".