Thread:Project:Support desk/Collapsible tables in vector/reply

They work fine in Vector.

However, one of your scripts in MediaWiki:Common.js is braking javascript execution. The following line to be exact: addOnloadHook(function {   document.getElementById("column-one").insertBefore( document.getElementById("p-tb"), document.getElementById("p-This_Page_On") ) })

returns null, as there is no such element in the Vector-skin. This kind of code should be moved to MediaWiki:Monobook.js (as it's skin-specific). The error is caused because  doesn't have a "insertBefore" property, and calling an inexisting function terminates JavaScript execution.

There's a couple more of these errors that are likely causing troubles which you may or may not have noticed. Aside from it belonging in Monobook.js, here's how code that uses methods on (potentially empty) objects should be written:

the exclamation mark means 'not'. the  means 'or'. So, the if-line sees if there are any needed elements missing. If so, return ("stop"). Any code after that can safely assume the elements exists.