"Unable to access the authentication service" while trying to add secured services.

Discussion created by memre on Nov 2, 2012
Latest reply on Jan 16, 2015 by stenarveesri-nl-esridist

I have a secured map service on my ArcGIS Server 10.1. When i tried to add my secured service layer to a web map in ArcGIS Online, the username/password page prompted with no problem. However when i try to login with my credentials, I got an error massage says that "Unable to access the authentication service".

Any ideas?