When I add my provider and consumer web parts to a web part page (following Walkthrough: Creating Connectable Web Parts in SharePoint Foundation) I find that the 'Connections' option on my webpart is disabled. I hover over the option to see the tooltip
The Web Part you are connecting from does not allow authoring of connections.
What causes this message to appear, and how can I fix it?
This error simply means that the web part being edited does not support connections - it has not been coded correctly.
In this case I was receiving the error because I placed the ConnectionProvider and ConnectionConsumer attributes and methods on the UserControl objects inside the Web Parts, rather than the Web Parts themselves.
You also cannot have connectable web parts in a Sandbox solution. It will not throw any error, you will se the "Connections" menu but it will be always disabled.
To change this go to your Project properties window (F4) and change the Sandboxed Solution property to "False", in next deployment things will work fine.
