I get this error when pushing our website to our clients production server however the page works absolutely fine on their dev / test servers. What causes this error (consideri
The error in the end was due to some URL re-writing that was occuring the server to which the admins hadn't told us about.! Watch out for that one
I used to get this annoying error all the time. Users are indeed affected by this error. We used to get complaints of pages not loading properly. After trying many things like adding DOCTYPE
the error did not go away completely. Then we tried storing all the VIEWSTATE
in session. Violà no more errors. If your application has a bloated view state like ours then you will see this error in the logs. Often.
Can you get a full stack trace on this error? There will be one in the server event log (system or application, can't remember which)?
There are various parts of ASP.NET that use script resources, and at least two slightly obscure causes of them failing with this sort of error I can think of.
There are lots of other causes (such as incorrect uris, or querystrings getting corrupted as mentioned above), but having a full stack trace will help here.
If indeed you are using multiple servers try the following: Add to your web.config:
<machineKey
validationKey="21F090935F6E49C2C797F69BBAAD8402ABD2EE0B667A8B44EA7DD4374267A75D7
AD972A119482D15A4127461DB1DC347C1A63AE5F1CCFAACFF1B72A7F0A281B"
decryptionKey="ABAA84D7EC4BB56D75D217CECFFB9628809BDB8BF91CFCD64568A145BE59719F"
validation="SHA1"
decryption="AES"
/>
But generate the validationKey and decryptionKey yourself using the code examples found here: http://msdn.microsoft.com/en-us/library/ms998288.aspx The above link also explains more about this solution so check it out, look for Web Farm Deployment Considerations on that page
You can check the urls which were generating this error. Web resources (used by the Ajax Toolkit) rely on a query string argument. If that argument is altered in some way (perhaps by some malicious user) the HTTP handler will throw exception that it cannot find the requested web resource.