When executing Claims Authentication powershell scripts (these are provided in the documentation, see Installation and Configuration > Configuration > SharePoint > Claims-based Authentication > Claims Authentication Configuration), an error will occur if the specified site contains more than one Additional Access mapping (CA -> System Settings ->Alternate Access Mappings).
Run a powershell script used to generate the claims XML section that goes in the K2HostServer.config to support incoming claims
Authentication With Server Failed : SAML Token could not be verified. Please ensure your config is setup correctly
Modified powershell scripts have been created to cater for additional access URLs. The updated script is available in the documentation contained in the latest K2 Update