‘Sys’ is undefined or ASP.NET Ajax client-side framework failed to load in a ASP .NET 4.0 website
18 November, 2010
12 Comments
I was getting the the error ['Sys' is undefined] and [ASP.NET Ajax client-side framework failed to load] in an ASP .NET 4.0 website. After reading and following the post [http://weblogs.asp.net/chrisri/archive/2007/02/02/demystifying-sys-is-undefined.aspx] I found my solution. De…