I am facing this odd problem. What I did (mistakenly though) was that I initially created some text fields for a content type and created lots of content for those fields. Now I want to change the formatting of the contents of those fields, mainly changing fonts and making it bold,so as to match the style of the content of other fields on the same node. With this in mind I changed the setting of the relevant text fields to filtered text but after doing so the editor appears but the content of the text field disappears and the text area which appears does not take/save new content.
Please help me from falling into the lengthy task of deleting all those test fields and recreating it with field type Long Text and then re add content to each of those fields on each node.