Feb 28, 2012 04:44 AM|KhD|LINK
Thank you for the links Chetan. I've seen them all and tried every solution.
I have tried:
--adding reference to the dll manually.
--registering the assembly on the page, and/or in web.config
--adding controls in toolbox and dragging and dropping to the page (which automatically registers the dll)
--deleting schema files and restarting VS2010.
--downloading AjaxControlToolkit using NuGet.
Nothing seems to be working. I simply cannot get the controls to work.