PRB: Image Uploader ASP.NET generates “Operation is not valid due to current state of object” error

You can upload limited number of files (about 45) per a single POST request. If you upload more than 45 files, the uploading process will stop and you will get the error. Java Console shows this dump:

[InvalidOperationException]: Operation is not valid due to the current state of the object.
at System.Web.HttpRequest.FillInFormCollection()
at System.Web.HttpRequest.get_Form()
at System.Web.HttpRequest.get_HasForm()
at System.Web.UI.Page.GetCollectionBasedOnMethod(Boolean dontReturnNull)
at System.Web.UI.Page.DeterminePostBackMode()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
[HttpUnhandledException]: Exception of type 'System.Web.HttpUnhandledException' was thrown.
at System.Web.UI.Page.HandleError(Exception e)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.myaccount_addphoto_aspx.ProcessRequest(HttpContext context) in c:\WINDOWS\microsoft.net\Framework64\v2.0.50727\Temporary ASP.NET Files\root\7ddb551a\66c2b18\App_Web_qcarljui.6.cs:line 0
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Reasons:

You installed the Windows Update recently: Microsoft Security Bulletin MS11-100.

The bulletin fixes the DOS attack vector by providing a limit to the number of variables that can be submitted for a single HTTP POST request. The default limit is 500.

Resolution:

This problem can be resolved in two ways:

1. Reconfiguring Image Uploader and server-side script to send all files in upload list into multiple packages (FilesPerPackage property should be set to some small value (e.g. 1-10))*.

2. Modifying applicationHost.config file. Go to C:\Windows\System32\inetsrv\config\applicationHost.config and add the following section to the config file, like it is shown in this code:
   Code:

   
   <appSettings>
       <add key="aspnet:MaxHttpCollectionKeys" value="10000" />
   </appSettings>
   

   It will allow increasing the number of variables that can be sent in a single HTTP POST request.

   ________

   * - The second way still has limitation. If you send all files in a single request, number of variables posted in a request depends on number of files. This way, increasing the value in config will give a temporary solution. Anyway it can be found amount of files causing this exception again. To eliminate even a chance of this problem you need to consider the first way.

Edited by moderator Thursday, June 20, 2013 9:20:13 PM(UTC)  | Reason: Not specified