I get the “Timer Set!” message, so I know execution is passing through SetTimer, but I never receive the “Invisible!” message, and the object never hides itself, so my assumption is that SetTimer isn’t calling the HideUI function- is there an obvious mistake with how I’m doing this?
first simple check you can try is copy/past your function name right into set timer, because you may miss extra hidden spaces, for example your function exactly “HideUI”, but in set timer it can be occasionally "HideUI " then more likely set timer won’t tell you if he doesn’t found such function or he actually say it to you, but you didn’t open hidden by default output log, open it here:
on world editing window there’s top button “window”->“Developer tools”->“Output log”, in this log you may find many usefull warning during playing and even right in editor
p.s. don’t forget mark question as answered when problem solved, so anyone else later can have same question and may find solution faster, if you find solution on your own, don’t forget write it too