The Agent is not able to get a list of Task Servers back from the Notification Server resulting in the Agent not being able to register with a Task Server.
Error code: HTTP error occured (0x80042D21)
Error note: Authentication failed, request level authentication is not supported, check that IIS setting 'authPersistNonNTLM' is set to 'True' on the server
Error code: HTTP status 200: The request has succeeded (0x8FA100C8)
Error note: Empty response content received
ITMS 8.5 RU1
When Windows Authentication is set to Authenticate, additional settings for Kerberos are needed to function properly.
If the customer want's to use Kerberos then other settings are needed such as setting up Service Principal Names (SPN) for each ITMS node (Notification Server and Site Servers). If Kerberos is not desired we should switch Windows Authentication to use NTLM instead of Authenticate.