Good day, I have encountered a rather strange issue with SharePoint 2010 and Content Editor Web Parts.
When you click the Edit Page button on the Site Action drop down menu, the page is checked out and in edit mode, but clicking the Add a Web Part link does nothing. The add a web part ribbon does not show, not even when you click the Web Part button in the Web Parts section in the Insert Page Tools tab.
This only happens when the page was published and you edit the page, and only when the page already has a CEWP. When you edit a checked out page and click the add web part button the web part ribbon will show, or if you first edit an existing web part on the page and then click the add web part hyperlink. None of the other web parts causes the same issue.
The only difference that I cold find was when you edit a published page the _wpSelected and _wzSelected hidden fields will have an empty string as the value, but if you first edit an existing web part the hidden fields will have a value.
Using fiddler I checked that all the content loads, there are no http 400 or http 500 errors.
Any suggestions will be greatly appreciated