Master Page Weirdness - “Content controls have to be top-level controls in a content page or a nested master page that references a master page.”

Question

This is weird. I added a brand new Web Application project to my solution in Visual Studio 2008.

Created a master page. Made zero modifications. Created a new we

Answer 1

In my case I was loading a user control dynamically in a page and both the page and user control had the content tags

Removing this tag from the user control worked for me.