Ajax Error: Sys.WebForms.PageRequestManagerTimeoutException

Problem:

I was working in a project, an ASP.NET web project which is Ajax enabled. While debugging the code I got this error: Sys.WebForms.PageRequestManagerTimeoutException

Cause:

The cause of this problem is that the Ajax extensions framework has its callback timeout set to 90 seconds by default so when you put breakpoint and while debugging the code, if your time exceeded the 90 seconds, it will show that error. This error could happen of you retrieve huge data that exceeds the 90 seconds or any other scenario.

Resolution:

In order to solve this, you have to set the “AsyncPostBackTimeOut” for the script manager to your preferred period in seconds like this:

<^asp:ScriptManager ID="ScriptManager1" runat="server" AsyncPostBackTimeout="1200"^>

And that’s it.

Regards,

Hamzeh Ayesh