Security Token Service is not available (I fixed it)

After having a fresh installation of SharePoint 2010 i was facing the following error in my Security Token Service. I tired multiple solutions but could not fix my issue. Finally a thread helped me out to solve my problem.

Note: This solution worked for me. I had a fresh installation of SharePoint 2010 without SP1 and any update. It was completely OOB.

If one tries to visit standard web service such as SecurityTokenServiceApplication (http://localhost:32843/SecurityTokenServiceApplication/SecurityToken.svc , orhttps://localhost:32844/SecurityTokenServiceApplication/SecurityToken.svc ), the service will respond withSystem.InvalidOperationException

Error: Security policy export failed. The binding contains a TransportSecurityBindingElement but no transport binding element that implements ITransportTokenAssertionProvider. Policy export for such a binding is not supported. Make sure the transport binding element in the binding implements the ITransportTokenAssertionProvider interface. ----> System.InvalidOperationException: Security policy export failed. The binding contains a TransportSecurityBindingElement but no transport binding element that implements ITransportTokenAssertionProvider. Policy export for such a binding is not supported. Make sure the transport binding element in the binding implements the ITransportTokenAssertionProvider interface.

Solution:

Go to the STS web.config (please make sure you have a backup of it) and alter the authentication mode of the spStsActAsBinding from SspiNegotiatedOverTransport to IssuedToken.

For more information please visit the following:

http://social.technet.microsoft.com/Forums/is/sharepoint2010setup/thread/b9d8c265-6397-4667-a6f9-2953ea64adef