to add a custom tab in the ribbon. After deploying my solution the tab appears fine and everything seems to be working.
What i did next was , I took the RegistrationId="101" RegistrationType="List" from the XML definisiton and called the MakeTabAvailable method as follows hoping that i can make the tab available in all lists.
protected void Page_Load(object sender, EventArgs e)
SPRibbon ribbon = SPRibbon.GetCurrent(this.Page);
however after doing that, the tab appears fine, but it can't load the groups/buttons. The tab just keeps on loading and nothing is rendered. If i click on another tab, and then click on my custom tab i get the following error in the browser.