Sys.WebForms.PageRequestManagerTimeoutException

when I tried to export an image, i got this error: "Sys.WebForms.PageRequestManagerTimeoutException The server request timed out"

from the Ajax Extension framework. Its occurred because the export operation was relatively long (something like 2 minutes) and the Ajax Extension Callback framework had a timeout.

How to solve this problem?

To solve this problem we can increase the timeout. You can change the timeout time by adding a new property to the script manager control. This property is called AsyncPostBackTimeOut and it can help us to define the number of seconds before the request will throw a request timeout exception.

For example if you want that the timeout will take maximum 10 minutes your code should be look like this:

<asp:ScriptManager ID="ScriptManager1" runat="server" AsyncPostBackTimeOut="600" ></asp:ScriptManager>