I’m using Keyboard Maestro 8.0.3 on an Mac with macOS 10.12 Sierra.
Since a couple of days the Keyboard Maestro Editor window opens on its own whenever I start my Mac. I have (and always had) the Keyboard Maestro Engine in my Login Items but I don’t have the Keyboard Maestro Editor there.
I changed two things a couple of days ago: 1.) I changed the Dropbox preferences so that Dropbox starts at computer startup. 2.) I updated the Fujitsu ScanSnap “Receipts” software. I have no Dropbox related Keyboard Maestro shortcuts or other things, but I do have several ScanSnap software related shortcuts (and the actual ScanSnap scan software starts at computer startup).
I now changed the Dropbox preferences back to its previous state (of not starting at computer startup) and restarted the computer.
Result: No Keyboard Maestro Editor window opened automatically (but the engine, of course, started as usual).
The same thing started happening to me as well. Keyboard Maestro used to start up in my menu bar and then in December every time I restart the editor window opens.