Currently if IOException is thrown from NegotiationAuthenticator (For example from line 123 from statement: NegotiationMessage requestMessage = mf.createMessage(authTokenIS); )
then this exception is never logged but it's catched and ignored in CoyoteAdapter.service. Result is that client receives response code 200 OK and emtpy HTTP response. And there is nothing in server log, which can be used to recognize error. So I need to debug if I want to find the real cause of IO issue.

Example for simulating of this issue can be using of Kerberos OID instead of SPNEGO OID as described in Jira SECURITY-572