I have been searching for a similar problem but no such luck on a straightforward answer. The post below is the closest I'v come to thus far: Loading Nested UserControls in ASP.NET
My problem to be specific is that my inner nested UserControl is what is being displayed, my outerUserControl does not display at all (it's an Ajax TabContainer) and that outerControl is supposed to load the table generated by my innerUserControl and display inside a TabContainer.
I have tried the methods listed in this previous post such as adding the reference and loading from the outerControl to no avail. Any help would be appreciated and information needed to aid in the solution I will attempt to provide. Again as in the previous post, general answers would help. I am using .NET 3.5 framework.