Trailing Hash (#) In URL Breaks Some Javascript?

I ran into a real head scratcher recently while trying to debug an issue with our Magento store. Some of the in-line javascript in one of the template files wasn't running and I c

Solution 1:

it is most likely the js you use parses the URL and try to match the end part (query or whatnot) to a specific string. once the # got added the string no longer matches and so it does not work.

of course, it could be other things but without seeing sample code that was my first thought