Symptom: the main DMX UI remains blank
Note the first thing to try is to refresh your browser as the Javascript file has been edited and this does not always automatically refresh on your browser. So press F5 first and your browser should redownload the new JS files. Second step: empty temporary internet files. That does the same but more rigorously.
If the problem persists you probably are using DNN 4 and a legacy skin. A legacy skin is rendered in old HTML 4 and not XHTML to the browser.
Legacy Skins and DNN 4
DNN 5.3 introduces sprites as mentioned above. This makes a significant shift in dependencies on the technology used for the skin and the browser. It was tested with FF, Chrome, IE 7 and 8 in various modes and various skins. The only problem we faced was IE in quirks mode on legacy skins. Here the main treeview would not show any icons, nor the menu. The lack of icons in the menu we felt was not important enough to delay release. But time was spent on getting the treeview to render icons. This involved a hack which uses jQuery.
jQuery is present in DNN 4.9.2 and later. But it turns out that in DNN 4 it is not included in the page output. Plus: the $ shortcut doesn't work in DNN 4 either. So the included hack doesn't work out of the box in DNN 4 (note this only concerns non-XHTML skins).
The solution is as follows:
1. Go to page settings on the page where DMX is and add reference to jQuery to Page Header Tags: see this post by Joe Brinkman
2. Open DesktopModules/Bring2mind/DMX/js/ViewCollection.js in a text editor and replace every $ with jQuery so the function repairTreeClasses becomes this:
function repairTreeClasses(){if(b_mode=='Q'&&CA_IE){jQuery('table.TreeNode tbody tr td[vAlign=middle]:not([class])').attr('class',function(){return jQuery(this).parent().parent().parent().attr('class')});jQuery('table.TreeNode tbody tr td[vAlign=middle]').removeClass('TreeNode');jQuery('table.TreeNode').attr('class','TreeNode');}}