Improve the message for failure to find LTI in the session.
Improve the message for failure to find LTI in the session.

tsugiproject/tsugi,JANQLIANGTSAI/tsugi,cvanlent/tsugi,reysantos/tsugi,JANQLIANGTSAI/tsugi,reysantos/tsugi,tsugiproject/tsugi,komizutama/tsugi,reysantos/tsugi,JANQLIANGTSAI/tsugi,komizutama/tsugi,tsugiproject/tsugi,csev/tsugi,cvanlent/tsugi,tsugiproject/tsugi,cvanlent/tsugi,komizutama/tsugi