diff --git a/mod/assign/tests/externallib_test.php b/mod/assign/tests/externallib_test.php
index 0dd6de1c140..78fa73e5565 100644
--- a/mod/assign/tests/externallib_test.php
+++ b/mod/assign/tests/externallib_test.php
@@ -1544,13 +1544,15 @@ class mod_assign_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/assign:view', CAP_PROHIBIT, $teacherrole->id, $context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_assign_external::view_grading_table($assign->id);
-            $this->fail('Exception expected due to missing capability.');
+            $this->fail('Exception expected due to missing view capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }
diff --git a/mod/folder/tests/externallib_test.php b/mod/folder/tests/externallib_test.php
index 14c3cb50dfc..17f0ba92da4 100644
--- a/mod/folder/tests/externallib_test.php
+++ b/mod/folder/tests/externallib_test.php
@@ -99,13 +99,15 @@ class mod_folder_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/folder:view', CAP_PROHIBIT, $studentrole->id, $context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_folder_external::view_folder($folder->id);
             $this->fail('Exception expected due to missing capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }
diff --git a/mod/imscp/tests/externallib_test.php b/mod/imscp/tests/externallib_test.php
index 4a2904f037f..14b5c68c89e 100644
--- a/mod/imscp/tests/externallib_test.php
+++ b/mod/imscp/tests/externallib_test.php
@@ -99,13 +99,15 @@ class mod_imscp_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/imscp:view', CAP_PROHIBIT, $studentrole->id, $context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_imscp_external::view_imscp($imscp->id);
             $this->fail('Exception expected due to missing capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }
@@ -168,10 +170,12 @@ class mod_imscp_external_testcase extends externallib_advanced_testcase {
         $contextcourse1 = context_course::instance($course1->id);
         // Prohibit capability = mod:imscp:view on Course1 for students.
         assign_capability('mod/imscp:view', CAP_PROHIBIT, $studentrole->id, $contextcourse1->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         $imscps = mod_imscp_external::get_imscps_by_courses(array($course1->id));
         $imscps = external_api::clean_returnvalue(mod_imscp_external::get_imscps_by_courses_returns(), $imscps);
-        $this->assertFalse(isset($imscps['imscps'][0]['intro']));
+        $this->assertCount(0, $imscps['imscps']);
     }
 }
diff --git a/mod/lti/tests/externallib_test.php b/mod/lti/tests/externallib_test.php
index 0fab2260393..51cd7b91d42 100644
--- a/mod/lti/tests/externallib_test.php
+++ b/mod/lti/tests/externallib_test.php
@@ -209,11 +209,13 @@ class mod_lti_external_testcase extends externallib_advanced_testcase {
         $contextcourse1 = context_course::instance($this->course->id);
         // Prohibit capability = mod:lti:view on Course1 for students.
         assign_capability('mod/lti:view', CAP_PROHIBIT, $this->studentrole->id, $contextcourse1->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         $ltis = mod_lti_external::get_ltis_by_courses(array($this->course->id));
         $ltis = external_api::clean_returnvalue(mod_lti_external::get_ltis_by_courses_returns(), $ltis);
-        $this->assertFalse(isset($ltis['ltis'][0]['intro']));
+        $this->assertCount(0, $ltis['ltis']);
     }
 
     /**
@@ -264,13 +266,15 @@ class mod_lti_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/lti:view', CAP_PROHIBIT, $this->studentrole->id, $this->context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_lti_external::view_lti($this->lti->id);
             $this->fail('Exception expected due to missing capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }
diff --git a/mod/page/tests/externallib_test.php b/mod/page/tests/externallib_test.php
index 128e363c4ed..075af6e9971 100644
--- a/mod/page/tests/externallib_test.php
+++ b/mod/page/tests/externallib_test.php
@@ -98,13 +98,15 @@ class mod_page_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/page:view', CAP_PROHIBIT, $studentrole->id, $context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_page_external::view_page($page->id);
             $this->fail('Exception expected due to missing capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }
diff --git a/mod/resource/tests/externallib_test.php b/mod/resource/tests/externallib_test.php
index 6b79da136f5..8ce41c4fc1c 100644
--- a/mod/resource/tests/externallib_test.php
+++ b/mod/resource/tests/externallib_test.php
@@ -99,13 +99,15 @@ class mod_resource_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/resource:view', CAP_PROHIBIT, $studentrole->id, $context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_resource_external::view_resource($resource->id);
             $this->fail('Exception expected due to missing capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }
diff --git a/mod/url/tests/externallib_test.php b/mod/url/tests/externallib_test.php
index dd8cd6e1990..686c4227466 100644
--- a/mod/url/tests/externallib_test.php
+++ b/mod/url/tests/externallib_test.php
@@ -98,13 +98,15 @@ class mod_url_external_testcase extends externallib_advanced_testcase {
         // Test user with no capabilities.
         // We need a explicit prohibit since this capability is only defined in authenticated user and guest roles.
         assign_capability('mod/url:view', CAP_PROHIBIT, $studentrole->id, $context->id);
+        // Empty all the caches that may be affected by this change.
         accesslib_clear_all_caches_for_unit_testing();
+        course_modinfo::clear_instance_cache();
 
         try {
             mod_url_external::view_url($url->id);
             $this->fail('Exception expected due to missing capability.');
         } catch (moodle_exception $e) {
-            $this->assertEquals('nopermissions', $e->errorcode);
+            $this->assertEquals('requireloginerror', $e->errorcode);
         }
 
     }