ADFS 3.0 form based authentication fails

Question

I am trying to configured ADFS for form based authentication.

When I try to login, I see the following error in the ADFS event viewer logs

S4U Logon for user with upn 'user@domain' threw the following exception: 'Insufficient system resources exist to complete the requested service'

Any advice is greatly appreciated

Answer 1

If the user is in another forest you need to ensure to use two way forest trusts instead of an external trust. Fba uses Kerberos s4u at adfs side. S4u only works with forest trusts. Get your active directory guy on this to check trust setup at the ad side for the impacted user account.