I wanna create Contextual Tab using Webpart In Sandbox Solution..that time I am getting Error as below When i am added Custom-Webpart :
Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trust app domain: An unexpected error has occurred.
In My Webpart's Code
Microsoft.SharePoint.WebControls.SPRibbon.GetCurrent(this.Page).MakeTabAvailable("MyProject.Ribbon.HelloTab");
Is there another way to Solution To create Custom Ribbon Tab?