Im getting that error when try to call a __doPostBack on one of my pages, every page that i have in the project use __doPostBack function but in this particular page im gett
__doPostBack() should be automatically included by any ASP.NET WebControl that could cause a post back. You sound like you are calling it manually in some Javascript you wrote. If so, you will need to include a WebControl, to make sure that function in inserted onto the page.