FCKeditor's SetHTML
method relies on a document.write
call to replace the content in the edit control. Unfortunately document.write
does not work from within the Web Console on Firefox.
This is a known bug: Using document.write inside Scratchpad window brings up 'Security error undefined' in Web Console
I know that error says Scratchpad and the error message is different but it's the same problem. Note this comment from David Chan (Mozilla Security Researcher):
This appears to be another bug from running WebConsole / ScratchPad in a sandbox.
The reason you probably remember being able to do this in the past is because it works in FireBug, and it works in Chrome. You've probably used one of those environments in the past when working with a FCKeditor control.