• ruderalos
  • 53% (Neutral)
  • YAF Forumling Topic Starter
12 years ago
After upgrading from to latest release RTW (which in itself was a challenge), forums are up and running. I am able to post new topics, edit old ones, update profiles, etc. However, trying to Save any of the configuration settings/changes from any of the Host Administration / Host Settings pages results in the following error listed below. Running on .NET 4.0, SQL Server 2005, IIS 6. Any ideas anyone? Thanks in advance for your help!

Server Error in '/' Application.

A potentially dangerous Request.Form value was detected from the client (forum$ctl03$AdPost="

..." ).

http://go.microsoft.com/fwlink/?LinkId=153133 .

Exception Details: System.Web.HttpRequestValidationException: A potentially dangerous Request.Form value was detected from the client (forum$ctl03$AdPost="

..." ).

Source Error:

The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL:

1. Add a "Debug=true" directive at the top of the file that generated the error. Example:

<%@ Page Language="C#" Debug="true" %>


2) Add the following section to the configuration file of your application:

Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode.

Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario.

Stack Trace:

[HttpRequestValidationException (0x80004005): A potentially dangerous Request.Form value was detected from the client (forum$ctl03$AdPost="

..." ).]

System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection) +8791012

System.Web.HttpRequest.ValidateNameValueCollection(NameValueCollection nvc, RequestValidationSource requestCollection) +122

System.Web.HttpRequest.get_Form() +150

System.Web.HttpRequest.get_HasForm() +8962943

System.Web.UI.Page.GetCollectionBasedOnMethod(Boolean dontReturnNull) +97

System.Web.UI.Page.DeterminePostBackMode() +69

System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +8431

System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +253

System.Web.UI.Page.ProcessRequest() +78

System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21

System.Web.UI.Page.ProcessRequest(HttpContext context) +49

ASP.default_aspx.ProcessRequest(HttpContext context) +4

System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +100

System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

  • ruderalos
  • 53% (Neutral)
  • YAF Forumling Topic Starter
12 years ago
Thank you Logan (and Jaben!). That worked! 🙂

<httpRuntime requestValidationMode="2.0" />

[and in case anyone else runs across this issue, please use Logan's exact spelling of the line (and the Microsoft error message), including the closing backslash "/>" at the end of the line. Otherwise, you will receive yet another Server Application error. I only found this out after following Logan's link to the previous thread 11 months ago and used Jaben's answer "", which did NOT include the closing backslash (sorry Jaben). Apparently, proper syntax matters. Who would of thought? :cheesy: ]

  • jpweber
  • 94.4% (Exalted)
  • YAF Commander
12 years ago
I had the exact same error when saving host settings. I downloaded YAF from the MS Web Platform Installer clean; it wasn't an upgrade.

Nevertheless, the solution worked perfectly, and m host settings are now being saved properly without errors.

Thank you for taking the time to help!

Jason Weber

USS Vision Inc.


Jason Weber

USS Vision YAF 

"Money is better than poverty, if only for financial reasons"