CodeEditor's cookie toggle mechanism is not implemented correctly and causes massive problems with other editors (such as missing edit areas with wikEd).
CodeEditor sets a cookie to signal that it is active on an edit page (wikiEditor-0-codeEditor-enabled = 1). This cookie is also used to toggle the editor's activation state.
Problem: CodeEditor is active by default, even if the the cookie is absent. However, CodeEditor does not recreate the missing cookie. CodeEditor is then active without the cookie and without an easy mechanism for other editors to detect its active presence. For wikEd, this leads to edit pages without any editing area (see https://en.wikipedia.org/wiki/User_talk:Cacycle/wikEd#WikEd_conflicts_with_code_editor).
Solution: Either CodeEditor has to recreate the cookie when it activates itself in the absence of the cookie or CodeEditor should stay inactive in the absence of the cookie.