I have recently upgrade our test environment to SP 2010 (using DB detach and attach approach). And also we did not do the Visual Upgrade. We have few CEWP's which is now starting throwing JS script error on click of the Button 'Rich Text Editor' in the Webpart tool pane.
Finally realized that error is coming from the file 'RTE2PUEditor.aspx'. As a standard we generally do not modify the sharepoint system and following the same stance here.
I have a strong feeling that this could be a issue from SP 2010 Beta and hoping further releases will have a fix for this.
Can someone confirm if my understanding is correct, and if not what could be fix for this.
Error: "Object Expected" Line no: 923 File Name: RTE2PUEditor.aspx Char: 1 Code: 0