It seems like there might be a mismatch or misconfiguration in the certificate settings between ADFS and OWA. Here's a suggested solution:
- Verify that the certificate configured in ADFS for Token-Decrypting and Token-Signing is the same as the one configured in OWA for encryption and signature. Also Ensure that the certificate being used for decryption in OWA is valid and trusted.
- In ADFS, ensure that the relying party trust for OWA is correctly configured with the appropriate encryption and signing certificates.
- Double-check the settings to confirm that the correct certificate is selected for decryption in the relying party trust configuration.
- Validate the certificates being used by both ADFS and OWA to ensure they are not expired, revoked, or otherwise invalid.
- Ensure that the certificate chain is complete and all intermediate certificates are properly installed
- Confirm that the thumbprint of the certificate configured in OWA matches the thumbprint of the certificate used by ADFS for token decryption.
- Continue reviewing logs and error messages in both ADFS and OWA for any additional clues or errors that might help diagnose the issue further.
- Enable verbose logging if necessary to capture more detailed information about the SAML requests and responses.