Hi Peter,
We have noted in some cases when users try to download files
we get the following error in the event log:
Server cannot set content type after HTTP headers have been sent.

Please advice.


Full details:

Event message: An unhandled exception has occurred.

Application information:
Application domain: /LM/W3SVC/1/ROOT-1-129519547859936677
Trust level: Full
Application Virtual Path: /
Application Path: C:\Sites\ABC\wwwroot\

Process information:
Process ID: 8900
Process name: w3wp.exe
Account name: IIS APPPOOL\ABC

Exception information:
Exception type: HttpException
Exception message: Server cannot set content type after HTTP headers have been sent.

Request information:
Request URL: http://ABC.com/DesktopMod...PortalId=0&TabId=805
Request path: /DesktopModules/Bring2mind/DMX/Download.aspx
User host address: XXX
User: XXX
Is authenticated: True
Authentication Type: Forms
Thread account name: IIS APPPOOL\ABC

Thread information:
Thread ID: 11
Thread account name: IIS APPPOOL\ABC
Is impersonating: False
Stack trace: at System.Web.HttpResponse.set_ContentType(String value)
at System.Web.UI.Page.SetIntrinsics(HttpContext context, Boolean allowAsync)
at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.errorpage_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpServerUtility.ExecuteInternal(IHttpHandler handler, TextWriter writer, Boolean preserveForm, Boolean setPreviousPage, VirtualPath path, VirtualPath filePath, String physPath, Exception error, String queryStringOverride)

We are runing DMX 5.2.11 on DNN 5.4.4

Did the download happen? The error is a generic error meaning that the server was apparently not done sending data to the client but the start of the page had already been sent. It could very well be that it is not critical but just clogs up your event log. In any case this is something that was resolved later as I've not heard about this error in DMX 5.3+

Peter

We're seeing it with several installations of DMX 5.3.7. For example, I'm looking at the windows application logs with one of the sites right now, and estimate that this has hit the log around 2500 times today.

The error is indicative of some kind of exception that happens after DMX has told the client: "I'm going to serve you file XYZ and it will be so many bytes". The exception can be anything. DNN will attempt to add some kind of error message but the headers have been sent and IIS complains about this. One scenario I can think of is if the original file is no longer found for instance. Then the streaming of the file gets broken off and an exception is thrown. Ultimately you'll need to dig and see if you can find anything we can go on to find out more about this issue.

Peter