I needed to retool macros that use app launch triggers

[Sleepy]

@anamorph

As soon as I posted, the answer presented itself. KM has changed the way it returns the application name when triggering from an app launch. It used to return the app name only, like TextEdit. Now it returns /Applications/TextEdit.app.

I searched for the release notes for KM9 and it does provide a related warning: (see yellow text below which comes form that page)

Keyboard Maestro 9

Keyboard Maestro version 9.0 adds support for Dark Mode, multiple editor windows, JSON, OCR, Stream Deck, and extended regex, as well as adding triggers, many actions, more palette themes, enhancing the editor and the clipboard switcher, improving performance, and more. Keyboard Maestro 9.x requires OS X El Capitan 10.11.0 or later. Version 9 is a paid upgrade for everyone who purchased before 1 February 2019. Version 9 is a free upgrade for anyone who purchased after 1 February 2019. Major …

==* Changed Application trigger to set TriggerValue to the path of the application. (may break macros)==

It sounds like this may have been your issue. If so, I wonder if future release notes could put anything that explicitly "may break macros" into a special section of the release notes so that it's brought more prominently to our attention. At least the release notes do say "may break macros" which is very honest and helpful. but maybe a little more prominence is needed for us.

I will even go one step further and suggest that any actions which are changed by a KM upgrade in such a way that they "may break macros" should be automatically highlighted in red (or maybe a unique colour) so that we know there could be a problem. If I saw an action highlighted in some odd colour (say red/blue stripes) that would sure get my attention. And I could easily set the colour to normal once I validate that the action still works.