Index: lams_central/conf/language/lams/ApplicationResources_en_AU.properties
===================================================================
diff -u -re0265c3507ca12f61524934309a32092296fe601 -r0751e64daecb64ee15d7c004a66b3ad5c8b6e26a
--- lams_central/conf/language/lams/ApplicationResources_en_AU.properties	(.../ApplicationResources_en_AU.properties)	(revision e0265c3507ca12f61524934309a32092296fe601)
+++ lams_central/conf/language/lams/ApplicationResources_en_AU.properties	(.../ApplicationResources_en_AU.properties)	(revision 0751e64daecb64ee15d7c004a66b3ad5c8b6e26a)
@@ -893,4 +893,6 @@
 authoring.tbl.delete.mcq.prompt=Do you want to delete the RAT Question {0}?
 authoring.application.exercise.allow.multiple.responses  =Allow Multiple Responses
 authoring.application.exercise.allow.multiple.responses.tooltip  =When learners are allowed to select multiple answers the grade is the sum of the grade for all correct responses selected.
+message.teacher.role.not.recognized  =Please wait for a teacher to start the lesson. (You were logged in as a learner, as your current role does not conform LTI specification).
+
 #======= End labels: Exported 872 labels for en AU =====
Index: lams_central/src/java/org/lamsfoundation/lams/web/controller/LtiController.java
===================================================================
diff -u -r39c16d5d248419593b4012a0b9adb0adca43970d -r0751e64daecb64ee15d7c004a66b3ad5c8b6e26a
--- lams_central/src/java/org/lamsfoundation/lams/web/controller/LtiController.java	(.../LtiController.java)	(revision 39c16d5d248419593b4012a0b9adb0adca43970d)
+++ lams_central/src/java/org/lamsfoundation/lams/web/controller/LtiController.java	(.../LtiController.java)	(revision 0751e64daecb64ee15d7c004a66b3ad5c8b6e26a)
@@ -148,12 +148,13 @@
 	//check if learner tries to access the link that hasn't been authored by teacher yet
 	String method = request.getParameter("_" + LoginRequestDispatcher.PARAM_METHOD);
 	if (LoginRequestDispatcher.METHOD_LEARNER_STRICT_AUTHENTICATION.equals(method) && extLessonMap == null) {
-	    String errorMsg = "Learner tries to access the link that hasn't been authored by teacher yet. resource_link_id: "
-		    + tcGradebookId;
-	    log.debug(errorMsg);
-	    request.setAttribute("error", errorMsg);
-	    request.setAttribute("javax.servlet.error.exception", new UserAccessDeniedException(errorMsg));
-	    return "error";
+	    String roles = request.getParameter(BasicLTIConstants.ROLES);
+	    //try to detect monitor with custom roles not supported by LTI specification
+	    String messageKey = roles.contains("Instructor") || roles.contains("Admin") ? "message.teacher.role.not.recognized"
+		    : "message.lesson.not.started.cannot.participate";
+
+	    request.setAttribute("messageKey", messageKey);
+	    return "msgContent";
 	}
 
 	//determine whether to show author or learnerMonitor pages