The warning message that you posted shows that authentication worked. Note that the reason the warning message is displayed is because you have $debug_lti_parameters = 1 in your authen_LTI.conf file. Set that to 0 for production usage. Then the warning will not be shown.
WeBWorK Main Forum
LTI WeBWorK - BlackBoard
This forum has a limit to the number of forum postings you can make in a given time period - this is currently set at 10 posting(s) in 1 day