Server cannot append header after HTTP headers have been sent.

Question

User24748943 posted

hi.

i have a web forms app (deployed to azure) that was created using vs 2013 update 2. i have also injected elmah into the app. now it seems something is wrong with the way authentification works: _sometimes_ i get the following exception notification from elmah:

System.Web.HttpException: Server cannot append header
after HTTP headers have been sent

System.Web.HttpException (0x80004005): Server cannot append header after HTTP headers have been sent.

   at System.Web.HttpHeaderCollection.SetHeader(String name, String value, Boolean replace)

   at System.Web.HttpHeaderCollection.Set(String name, String value)

   at Microsoft.Owin.Host.SystemWeb.CallHeaders.AspNetResponseHeaders.Set(String key, String[] values)

   at Microsoft.Owin.Host.SystemWeb.CallHeaders.AspNetResponseHeaders.set_Item(String key, String[] value)

   at Microsoft.Owin.Infrastructure.OwinHelpers.SetHeaderUnmodified(IDictionary`2 headers, String key, String[] values)

   at Microsoft.Owin.Infrastructure.OwinHelpers.AppendHeaderUnmodified(IDictionary`2 headers, String key, String[] values)

   at Microsoft.Owin.HeaderDictionary.AppendValues(String key, String[] values)

   at Microsoft.Owin.ResponseCookieCollection.Append(String key, String value, CookieOptions options)

   at Microsoft.Owin.Security.Cookies.CookieAuthenticationHandler.<ApplyResponseGrantAsync>d__b.MoveNext()

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   at Microsoft.Owin.Security.Infrastructure.AuthenticationHandler.<ApplyResponseCoreAsync>d__8.MoveNext()

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   at Microsoft.Owin.Security.Infrastructure.AuthenticationHandler.<TeardownAsync>d__5.MoveNext()

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   at Microsoft.Owin.Security.Infrastructure.AuthenticationMiddleware`1.<Invoke>d__0.MoveNext()

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   at Microsoft.AspNet.Identity.Owin.IdentityFactoryMiddleware`2.<Invoke>d__0.MoveNext()

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   at Microsoft.AspNet.Identity.Owin.IdentityFactoryMiddleware`2.<Invoke>d__0.MoveNext()

--- End of stack trace from previous location where exception was thrown ---

   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar)

   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.EndFinalWork(IAsyncResult ar)

   at System.Web.HttpApplication.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

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




I _think_ this happens when i'm logged into the site (into a protected directory, auth with forms), and close the browser or move to a different site.
any ideas what would be causing this or what to do to get rid of this?

WM_THX

-thomas woelfer

Answer 1

User-734925760 posted

Hi,

According to your description and the error message, please refer to make sure the version of the DNN. So far as I know, this error will happen with some compresssion/whitespace filter settings in DNN 4.4.x,  this has been corrected in DNN 4.5.  So please refor to upgrade the version.

Hope it's useful for you.

Best Regards,

Michelle Ge

Answer 2

User24748943 posted

Michelle,

what is "DNN" ? My application is basically just the application that vs 2013 update 2 generated automatically for me with some minor changes... (plus elmah). Incase you refer the "DotNetNuke" - i'm not using this. As i said, this is just the barebones stuff vs generated...

WM_THX
-thomas woelfer

Answer 3

User-1579698385 posted

In case you haven't found the cause yet, I recently ran into this as well, and it appears to be due to an issue within Katana that should be fixed in a future release:

http://katanaproject.codeplex.com/discussions/540202