ASP.NET Ajax Error: Sys.WebForms.PageRequestManagerParserErrorException

Answer 1

There is an excellent blog entry by Eilon Lipton. It contains of lot of tips how to void this error:

Sys.WebForms.PageRequestManagerParserErrorException - what it is and how to avoid it

Read the comments too. There is a comment of somebody with the same problem: "I solved it changing server idle time of my app pool on IIS. It was only 5, so I incremented it and now works."

"The UpdatePanel control uses asynchronous postbacks to control which parts of the page get rendered. It does this using a whole bunch of JavaScript on the client and a whole bunch of C# on the server.

Asynchronous postbacks are exactly the same as regular postbacks except for one important thing: the rendering. Asynchronous postbacks go through the same life cycles events as regular pages (this is a question I get asked often).

Only at the render phase do things get different. We capture the rendering of only the UpdatePanels that we care about and send it down to the client using a special format. In addition, we send out some other pieces of information, such as the page title, hidden form values, the form action URL, and lists of scripts."

Most common reasons for that error:

1. Calls to Response.Write():
2. Response filters
3. HttpModules
4. Server trace is enabled
5. Calls to Server.Transfer()

Answer 2

I solved this exact same problem removing the Content-Type: form the Custom HTTP Headers section in the HTTP Headers tab in IIS. This was breaking the encoding of the page and somehow it affected Ajax in general.

The Content-Type I had configured in IIS was setting the encoding to ISO-8859-1.

Answer 3

This may be a little hacky, but it solved the issue for me. I didn't have any of the common reasons for the error, so I just put in this band-aid in the page load:

        if (Session.SessionID == "")             {
            Page.Session.Add("SessionID", Session.SessionID);
        }

Answer 4

Problem :

      Sys.WebForms.PageRequestManagerParserErrorException will occur when redirecting ur page ,lets say button click inside UpdatePanel in aspxAjax

Soln :

1. Add a "GoTo" button in ur aspx page where update panel is using and add it outside Update panel

1a. In ur code assign ur just registered userID to session variable , say Session["UseridJustregistered"]= Id from DB or UsernameField

1. respose.redirect("regSucces.aspx?urlid='"+Session["UseridJustregistered"]+"'");

2. Check if Session["UseridJustregistered"] is null or not

--> This is OLD Classic ASP way which can solve our problem , by the time microsoft find a solution we can tackle it this way <--