To resolve this issue, follow these steps:
- Go to ADFS Server and download FederationMetadata.xml.
- Navigate to the DSM Console > Administration > User Management > Identity Providers > SAML, and under Identity Providers double click the entry.
- Click Import Metadata XML and locate the FederationMetadata.xml
- Try logging in using ADFS: https://<ADFS_FQDN>/adfs/ls/IdpInitiatedSignOn.
- Log in using UPN format.
- Locate the upper right section to verify ADFS Login.