Sys.WebForms.PageRequestManagerServerErrorException 12031. Out of ideas - asp.net

Question

In a recent project we are currently getting 12031 errors. here is the complete error:
Sys.WebForms.PageRequestManagerServerErrorException 12031
the status code returned from the
server was 12031
The problem is, this doesn't happen all the time and we are unable to reproduce the error on development environment.
We use AJAX in our application and this exception happens on every page once in a while.
I've found a post on SO with the same problem and tried changing maxRequestLength to "1" to see if I constantly get the same error but I don't. Instead, I'm getting
Maximum request length exceeded.
So I'm starting to think that it is not related to maxRequestLength. I'm actually out of ideas. I have a ScriptManager in my MasterPage and its AsyncPostBackTimeout="240". That is the same amount of time (give or take). I get the 12031 error after 3,5 minutes of "nothing". I'm logging one of the pages and by logging, I mean logging every section of the page like "Page_Load is called" "xyz is called" etc and I have like 15 spots on the page for this. After user clicks a button and ScriptManager tries to do its job, no postback occurs, no logging happens. It is like the page wants to do a postback but too old to do it. Tries this for around 3,5 minutes and fails with the given error.
Please, if you have any ideas, HELP ME OUT .
Thank you

Answer 1

That error almost certainly has nothing to do with the size of the response, AsyncPostBackTimeout, or maxRequestLength.
Connection resets are usually indicative of poor network connectivity or a server loaded down to its capacity limits. A few things you could try:
Inspect the Windows Event Log during the time(s) that the kiosks were known to have received the error. Look for any relevant errors or warnings.
If feasible, ask the kiosk staff to use something like Pingtest to test the quality of their local network connection at the time that they receive the error in your app.
Use a service like Pingdom to ensure that the server itself isn't intermittently losing connectivity.

Answer 2

This error may be due to the HTTP Runtime limitation of the maxRequestLength. The default value is 4096.
Try adding (or editing) the following entry in your Web.Config:
"<httpRuntime maxRequestLength="8192" />" (effectively allowing 8mb of data transmission, instead of the default 4mb).
Please not....You can set data as per you max request. 8192 is not the limit. Also you need to add Page.Form.Attributes.Add("enctype", "multipart/form-data"); in Page_Load event of the page.
You'll want to enter this in the System.Web configuration section.
How do I avoid getting a PageRequestManagerParserErrorException?
To start with, don't do anything from the preceding list! Here's a matching list of how to avoid a given error (when possible):
Calls to Response.Write():
Place an or similar control on your page and set its Text property. The added benefit is that your pages will be valid HTML. When using Response.Write() you typically end up with pages that contain invalid markup.
Response filters:
The fix might just be to not use the filter. They're not used very often anyway. If possible, filter things at the control level and not at the response level.
HttpModules:Same as response filters.
Server trace is enabled:
Use some other form of tracing, such as writing to a log file, the Windows event log, or a custom mechanism.
Calls to Server.Transfer():
I'm not really sure why people use Server.Transfer() at all. Perhaps it's a legacy thing from Classic ASP. I'd suggest using Response.Redirect() with query string parameters or cross-page posting.
Another way to avoid the parse error is to do a regular postback instead of an asynchronous postback. For example, if you have a button that absolutely must do a Server.Transfer(), make it do regular postbacks. There are a number of ways of doing this:
The easiest is to simply place the button outside of any UpdatePanels. Unfortunately the layout of your page might not allow for this.
Add a PostBackTrigger to your UpdatePanel that points at the button. This works great if the button is declared statically through markup on the page.
Call ScriptManager.RegisterPostBackControl() and pass in the button in question. This is the best solution for controls that are added dynamically, such as those inside a repeating template.
Good luck!

Answer 3

I have received this error before when we had a Barracuda Device sitting in front of our website. It was a maximum request length issue because Barracuda protects against overloading the request size. We removed the device temporarily and it solved the problem. Not sure if this is your problem.