diff --git a/group/externallib.php b/group/externallib.php
index c44e784e6d1..0c17c81a57b 100644
--- a/group/externallib.php
+++ b/group/externallib.php
@@ -89,7 +89,7 @@ class core_group_external extends external_api {
             }
 
             // now security checks
-            $context = context_course::instance($group->courseid);
+            $context = context_course::instance($group->courseid, IGNORE_MISSING);
             try {
                 self::validate_context($context);
             } catch (Exception $e) {
@@ -168,7 +168,7 @@ class core_group_external extends external_api {
             $group = groups_get_group($groupid, 'id, courseid, name, description, descriptionformat, enrolmentkey', MUST_EXIST);
 
             // now security checks
-            $context = context_course::instance($group->courseid);
+            $context = context_course::instance($group->courseid, IGNORE_MISSING);
             try {
                 self::validate_context($context);
             } catch (Exception $e) {
@@ -235,7 +235,7 @@ class core_group_external extends external_api {
         $params = self::validate_parameters(self::get_course_groups_parameters(), array('courseid'=>$courseid));
 
         // now security checks
-        $context = context_course::instance($params['courseid']);
+        $context = context_course::instance($params['courseid'], IGNORE_MISSING);
         try {
             self::validate_context($context);
         } catch (Exception $e) {
@@ -318,7 +318,7 @@ class core_group_external extends external_api {
             }
 
             // now security checks
-            $context = context_course::instance($group->courseid);
+            $context = context_course::instance($group->courseid, IGNORE_MISSING);
             try {
                 self::validate_context($context);
             } catch (Exception $e) {
@@ -376,7 +376,7 @@ class core_group_external extends external_api {
             // validate params
             $group = groups_get_group($groupid, 'id, courseid, name, enrolmentkey', MUST_EXIST);
             // now security checks
-            $context = context_course::instance($group->courseid);
+            $context = context_course::instance($group->courseid, IGNORE_MISSING);
             try {
                 self::validate_context($context);
             } catch (Exception $e) {
@@ -456,7 +456,7 @@ class core_group_external extends external_api {
             $user = $DB->get_record('user', array('id'=>$userid, 'deleted'=>0, 'mnethostid'=>$CFG->mnet_localhost_id), '*', MUST_EXIST);
 
             // now security checks
-            $context = context_course::instance($group->courseid);
+            $context = context_course::instance($group->courseid, IGNORE_MISSING);
             try {
                 self::validate_context($context);
             } catch (Exception $e) {
@@ -534,7 +534,7 @@ class core_group_external extends external_api {
             $user = $DB->get_record('user', array('id'=>$userid, 'deleted'=>0, 'mnethostid'=>$CFG->mnet_localhost_id), '*', MUST_EXIST);
 
             // now security checks
-            $context = context_course::instance($group->courseid);
+            $context = context_course::instance($group->courseid, IGNORE_MISSING);
             try {
                 self::validate_context($context);
             } catch (Exception $e) {
diff --git a/mod/forum/index.php b/mod/forum/index.php
index aaea9159eaf..5d0b5c53bfe 100644
--- a/mod/forum/index.php
+++ b/mod/forum/index.php
@@ -129,7 +129,7 @@ foreach ($modinfo->instances['forum'] as $forumid=>$cm) {
 
     $forum = $forums[$forumid];
 
-    if (!$context = context_module::instance($cm->id)) {
+    if (!$context = context_module::instance($cm->id, IGNORE_MISSING)) {
         continue;   // Shouldn't happen
     }