NeatUpload Authentication Issue

Jun 30, 2011 at 7:51 PM

I am running into an intermittent issue with the NeatUpload control in which I am occassionally prompted to authenticate at the web server level when uploading the images.  I've tracked the HTTP requests to the server when this was occurring and see the failed authentication requests.  I reviewed the authentication header content within the Fiddler utility to try to see what the request were that were failing and requiring authentication.  The requests were to /NeatUpload/MultiRequestUploadHandler.ashx and I noticed that for the requests that succeeded, the auth header indicated 'No WWW-Authenticate Header is present' but for the ones that failed and forced the web server login prompt, the auth header indicated 'WWW-Authenticate Header is present: Negotiate.  WWW-Authenticate Header is present: NTLM'.  As a potentially related note, the server is IIS 6 running on Windows Server 2003 R2, Integrated Windows Authentication is enabled for the entire site, and the web.config for the NeatUpload file has a setting that sets UseFullyQualifiedRedirectUrl to true.

Please let me know if you have any insights into what may be causing this problem.  Thanks.

John Fleming