FCKEditor will stop working with FireFox 3.5.7, 3.6 and future releases. There is a “Year 2010” bug that breaks the regular expression method they use to find what browser you are using. I found this in FCKEditor v.2.6.4.1. ColdFusion 8 and 9 appears to be okay, however I would double check them.

The issues lies in the file fckutils.cfm located in the FCKEditor root install directory. It checks for your useragent such as “Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6”.

The glitchy code can be found on line 47:

stResult = reFind( "gecko/(200[3-9][0-1][0-9][0-3][0-9])", sAgent, 1, true );

Replace this line with:

stResult = reFind( "gecko/(20[0-9][0-9][0-1][0-9][0-3][0-9])", sAgent, 1, true );

This will give the expression another 90 years of matching. You can also pass “checkBrowser=false” to the FCKEditor component to disable this check.

If you don’t have a fckutils.cfm file, a similar line can be found in fckeditor.cfc.

Another “fix” is to upgrade to CKEditor as it’s a Javascript only add-on.