Hi. I'm running Moodle 2.5.1 and have encountered a bizarre issue. When a page in a course is being edited(by clicking on "Edit settings" under "Page module administration"), the html editor sometimes appears and other times it does not. I have narrowed it down to the fact that it always appears if editing is turned off, but never appears if editing is turned on. This happens consistently across all browsers that I have tested(Chrome, Internet Explorer, Firefox, Opera and Safari).
I have already purged all caches in Moodle as well as purged the theme cache. I've also looked through user roles and cannot seem to find anything there that would fix the problem. Does anyone know what could be the cause of this issue or how to remedy it?