Firefox Won't Work with FCKEditor or TinyMCE

Editor Loads in IE but not in Firefox

Firefox is a wonderful browser, streamlined, fast, efficient, and secure. But it can turn into a slow, inefficient resource hog when too many poorly designed extensions and addons are installed. In this case, the problem is that the TinyMCE or FCKEditors (WYSIWYG = What You See Is What You Get) editors would load fine in IE, Mozilla, and other browsers, but not in Firefox. At first it appeared that this issue was specific to the FCK and TinyMCE drupal modules, but then it turned out that not even the demo's on the FCKEditor and TinyMCE pages would work. In other words - FCKEditor and TinyMCE work fine in recent versions of all the major browsers. The problem below is a result of a conflict with other extensions:

JavaScript Errors

In my JavaScript Console the following errors would repeatedly occur when trying to load a page (such as the FCKEditor demo page) with FCK text area fields:

Error: navigator.appVersion.match(/MSIE (.\..)/) has no properties Source File: http://www.<domain-name>.com/modules/fckeditor/fckeditor/fckeditor.js Line: 144 </domain-name>

Tiny MCE also experienced two different JavaScript errors that I would have to reproduce to post here.

The Solution - Fresh Firefox Profile

The solution involves a Fresh install of Firefox, and in some cases a new profile. If a re-install of the Firefox executable (into a new folder) does not solve your problem, you may need to reinstall your profile. First back it up by renaming the "Firefox" folder (instead of deleting it) to "Firefox-bak" in the following folder:

C:\Documents and Settings\USERNAME\Application Data\Mozilla

This is for Windows systems - replace USERNAME with your username. Now when you reinstall Firefox a new profile will be generated and you should no longer experience the above error. Please post any comments or questions below.