Sometimes, rather than giving me a "friendly" warning that the app is unsigned, I get and exception with a stack trace, with:

    Termination Reason:    Namespace CODESIGNING, Code 0x1

I can (re)sign the application with:

    codesign --force --deep --sign - /path/to/The.app

which often resolves the issue.

but what's the difference between the error that causes the friendly warning, and the error that cases the stack trace/exception? Is this the difference between a lack of code signature and a failed check?