We are using RAD Grid, RAD Treeview, RAD Dock and bunch of other controls on a page. Based on node clicked on the treeview, the result in the grid changes. The entire page was working fine in .Net 3.5 perfectly fine. But when we migrated the application to .Net 4.0, the page started shouting.
Initially it gave JS errors as follow:
- Error: ASP.NET Ajax client-side framework failed to load.
- Error: 'Sys' is undefined
- Error: 'Telerik' is undefined
And even page was not rendered correctly. It was completely messed up.
After this we added
entry in web.config file under <handlers> section. After adding it, above errors are gone.
But now it is throwing following JS error when I click on the treenode.
Error: Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 500
Debugging shows following error which we caught in Application_Error :
A potentially dangerous Request.Form value was detected from the client (ctl00$maincontent$dockSearchCriteria$C$SearchAttributeRules1$hidRetVal="<Groups>
I am not able to understand why this error is coming and how to get rid of it..
Any help appreciated.