KEYS: as a label will stop AOZ from working
Having a label called KEYS: in a program and AOZ will not build new version in either Viewer or browser.
It will just run the previous old one with No displayed errors or messages.
To reproduce/test just add the line KEYS: in any program. Delete the line and it works again.
Variations like INKEYS: or KEYSS: however works fine so it's very specific.