diff --git a/group/lib.php b/group/lib.php
index 8fd4c127e4a80..6c9e52c28641c 100644
--- a/group/lib.php
+++ b/group/lib.php
@@ -646,11 +646,10 @@ function groups_get_members_by_role($groupid, $courseid, $fields='u.*',
                    u.id AS userid, $fields
               FROM {groups_members} gm
               JOIN {user} u ON u.id = gm.userid
-              JOIN {role_assignments} ra ON ra.userid = u.id
-              JOIN {role} r ON r.id = ra.roleid
+         LEFT JOIN {role_assignments} ra ON (ra.userid = u.id AND ra.contextid ".get_related_contexts_string($context).")
+         LEFT JOIN {role} r ON r.id = ra.roleid
              WHERE gm.groupid=:mgroupid
-                   AND ra.contextid ".get_related_contexts_string($context).
-                   $extrawheretest."
+                   ".$extrawheretest."
           ORDER BY r.sortorder, $sort";
     $whereparams['mgroupid'] = $groupid;
     $rs = $DB->get_recordset_sql($sql, $whereparams);
@@ -687,7 +686,7 @@ function groups_calculate_role_people($rs, $context) {
         if (!array_key_exists($rec->userid, $users)) {
             // User data includes all the optional fields, but not any of the
             // stuff we added to get the role details
-            $userdata=clone($rec);
+            $userdata = clone($rec);
             unset($userdata->roleid);
             unset($userdata->roleshortname);
             unset($userdata->rolename);
@@ -720,7 +719,7 @@ function groups_calculate_role_people($rs, $context) {
     $rs->close();
 
     // Return false if there weren't any users
-    if (count($users)==0) {
+    if (count($users) == 0) {
         return false;
     }
 
@@ -730,12 +729,18 @@ function groups_calculate_role_people($rs, $context) {
     $roledata->users = array();
     $roles['*'] = $roledata;
 
+    $roledata = new stdClass();
+    $roledata->name = get_string('noroles','role');
+    $roledata->users = array();
+    $roles[0] = $roledata;
+
     // Now we rearrange the data to store users by role
     foreach ($users as $userid=>$userdata) {
         $rolecount = count($userdata->roles);
-        if ($rolecount==0) {
-            debugging("Unexpected: user $userid is missing roles");
-        } else if($rolecount>1) {
+        if ($rolecount == 0) {
+            // does not have any roles
+            $roleid = 0;
+        } else if($rolecount > 1) {
             $roleid = '*';
         } else {
             $roleid = $userdata->roles[0]->id;
diff --git a/lang/en/role.php b/lang/en/role.php
index 6d2bb152d77a7..f992ba1dd31c6 100644
--- a/lang/en/role.php
+++ b/lang/en/role.php
@@ -224,6 +224,7 @@
 $string['nocapabilitiesincontext'] = 'No capabilities available in this context';
 $string['noneinthisx'] = 'None in this {$a}';
 $string['noneinthisxmatching'] = 'No users matching \'{$a->search}\' in this {$a->contexttype}';
+$string['noroles'] = 'No roles';
 $string['noroleassignments'] = 'This user does not have any role assignments anywhere in this site.';
 $string['notabletoassignroleshere'] = 'You are not able to assign any roles here';
 $string['notabletooverrideroleshere'] = 'You are not able to override the permissions on any roles here';
diff --git a/user/selector/lib.php b/user/selector/lib.php
index 02f879d657a0e..c6215dbc7988e 100644
--- a/user/selector/lib.php
+++ b/user/selector/lib.php
@@ -751,7 +751,7 @@ public function print_user_summaries($courseid) {
         global $DB, $PAGE;
 
         $usersummaries = array();
-        
+
         // Get other groups user already belongs to
         $usergroups = array();
         $potentialmembersids = $this->potentialmembersids;
@@ -792,10 +792,12 @@ public function find_users($search) {
 
         // Get list of allowed roles.
         $context = get_context_instance(CONTEXT_COURSE, $this->courseid);
-        if (!$validroleids = groups_get_possible_roles($context)) {
-            return array();
+        if ($validroleids = groups_get_possible_roles($context)) {
+            list($roleids, $roleparams) = $DB->get_in_or_equal($validroleids, SQL_PARAMS_NAMED, 'r00');
+        } else {
+            $roleids = " = -1";
+            $roleparams = array();
         }
-        list($roleids, $roleparams) = $DB->get_in_or_equal($validroleids, SQL_PARAMS_NAMED, 'r00');
 
         // Get the search condition.
         list($searchcondition, $searchparams) = $this->search_sql($search, 'u');
@@ -810,11 +812,9 @@ public function find_users($search) {
                             WHERE igm.userid = u.id AND ig.courseid = :courseid) AS numgroups";
         $sql = "   FROM {user} u
                    JOIN ($enrolsql) e ON e.id = u.id
-                   JOIN {role_assignments} ra ON ra.userid = u.id
-                   JOIN {role} r ON r.id = ra.roleid
-                  WHERE ra.contextid " . get_related_contexts_string($context) . "
-                        AND u.deleted = 0
-                        AND ra.roleid $roleids
+              LEFT JOIN {role_assignments} ra ON (ra.userid = u.id AND ra.contextid " . get_related_contexts_string($context) . " AND ra.roleid $roleids)
+              LEFT JOIN {role} r ON r.id = ra.roleid
+                  WHERE u.deleted = 0
                         AND u.id NOT IN (SELECT userid
                                           FROM {groups_members}
                                          WHERE groupid = :groupid)