Console Function Message

Sometimes when testing my game, the following is printed to the console:

function Function() []

Nothing seemingly happens when it does sometimes, but I have noticed it before. However, one of my behaviors stopped working correctly all of a sudden and I saw this printed to the console.

What does this mean?

Anybody have any ideas on this? I get it in the console when trying to return a response from a PHP script on a webserver and wandered about it.

When that happens, the game is failing to execute a custom event, usually.  Double-check your code and play around with it until it works.