In the ribbon, I want to insert a picture or a link into a content page, but the "From Sharepoint" button is grayed out and I can only upload an image or insert a link "From Address". My field is rich text. I'm using SharePoint 2010.
How can I make the link available? Thanks
Do not muck with the ribbon to make this work!
Totally depends on how you want to use it.
First of all, the Publishing feature must be active on Site Collection level and on the site where you want to add your rich content.
Then, if you activate the Wiki Home page feature you will have the SharePoint option availabe on the page. If you want to use it in a custom list, it gets a bit more complicated.
The normal Rich Text field greys out the SharePoint option. And you can not add the Full HTML with publishing field directly to a custom list. So the solution is to create a new site column based on the Full HTML field. And then add that site column to the custom list. This field is part of the publishing infrastructure. So only available on SharePoint Server 2010
Unless you have the "SharePoint Server Publishing feature" under "Site Settings" -> "Site Features" activated, these options are not made available to you.
Usually ribbon button is grayed out if you didn't add CommandUIHandler element for it in your CustomAction XML.
For more details, you can see this MSDN article:
http://msdn.microsoft.com/en-us/library/ff458385.aspx
Also, you can find useful this article (with sample code and screenshot):
