You receive this error message when attempting to view a page in your application:
Sys.WebForms.PageRequestManagerServerErrorException:
An unknown error occurred while processing the request on the server.
The status code returned from the server was: 404 ...
This error occurs when the table name has foreign characters. Then clicking any button might cause a javascript error.
To resolve this problem, go to the application generation option, General Application Options->Web Page Options->Page Controls->Smooth panel update to turn off smooth panel update.
OR:
Sys.WebForms.PageRequestManagerServerErrorException:
An unknown error occurred while processing the request on the server.
The status code returned from the server was: 500
Microsoft .Net Framework by default allows a limited number of fields, to be posted to a page, which is set to 1000. If there are more than the default number of fields posted, it results in an error. This can possibly happen when you have multiple Many-To-Many panels on the page.
To work around this issue, please add the following element to your AppSettings in your web.config:
<add key="aspnet:MaxHttpCollectionKeys" value="5000" />