Learning and Developing AppleScripts

[JMichaelTX]

@BernSh

Obvious question, why is KM not a reliable test platform for code?

Chris @ccstone gave you a great, thorough answer.
But simply put, KM is NOT a scripting editor or IDE for coding.

Chris' bottom line is worth repeating:

@ccstone

You should always write, proof, and debug AppleScript in a proper AppleScript editor.

Only then should you move your code to a Keyboard Maestro action.