I had a similar issue, worked fine when I was testing it on my machine, but I had dev tools open to see any potential issues.

Turns out IE8 doesn't define console until the devtools are open. That caused me to pull a few hairs out.

I can't remember the actual bug now, but one of my early career memories was hunting down an IE7 issue by using bookmarklets to alert() values. (Did IE7 even have dev tools?)

There was a downloadable developer toolbar for IE6 and IE7, and scripts could be debugged in the external Windows Script Debugger. The developer toolbar even told you which elements had the famous hasLayout attribute applied, which completely changed how it was rendered and interacted with other objects, which was invaluable.