Recently
I faced a strange issue in the process of development using script manager for
async post backs.
The error
is "webresource.axd and scriptresource.axd 404 not found”. Whenever I do any
async call I use to get this error "sys is not defined”. I have tried a lot to
fix this issue by following the below links and so on....
After
spending 4 hours I found a new property on asp.net 4.0 called EnableCdn that
basically, if it's set to "true", it loads the resources from the Microsoft
content resource servers.
Refer
this link (http://msdn.microsoft.com/en-us/library/system.web.ui.scriptmanager.enablecdn
(v=vs.100).aspx) for information about EnableCDN.
This
worked like a charm and fixed my issue.