This seems to fix the rest endpoint issue (esp. changes to outputs.conf). https://docs.splunk.com/Documentation/Splunk/latest/Updating/Upgradepre-9.2deploymentservers ... View more

Had the same error message to an adfs server with encryption and in my case this worked, dont know if it is correct. I added the encrypted private key to signAuthnRequest certificate, which  is this authentication.conf parameter: [saml] clientCert = cert_and_encrypted_private_key.pem The password of the encypted private key was configured to the parameter sslPassword of the same stanza  sslPasswort =  No this parameter could be set to true: signAuthnRequest = true and reloaded authentication to let the sslPasswort be hashed. Worked for me. ... View more

You can post the ask in ideas.splunk.com. ... View more