I have an issue with the WebTab control (2010.3) under ASP.Net; I have designed a user control containing a WebTab control; Each tab has a number of textboxes; the user control also has and a public property called CompanyId, which when set will cause the control to retrieve the Company details from the database and populate the textboxes (found across all tabs).

In the aspx page hosting the user control I have a ultrawebgrid listing all the companies and when I select one, I set the CompanyId of my User control to the selected item's key, and I can see that the textboxes are populated correctly in all tabs.

When I now select another item from the grid (or initiate a postback), I get an error "Object reference not set to an instance of an object.", and I can see that all my textboxes which I am trying to populate are all null and thus cannot be referenced by the code behind.

Is there a special way to handle postbacks while using the WebTab control? I previously had all my controls laid down on the user control surface without the WebTab and they worked fine.

I have used UltraWebTab in the past and this worked there as well..