diff --git a/scripts/lang_functions.php b/scripts/lang_functions.php
index 56158a469..af1e2ab3b 100644
--- a/scripts/lang_functions.php
+++ b/scripts/lang_functions.php
@@ -316,7 +316,7 @@ function save_key($key, $value, $path) {
     $file = file_get_contents($filePath);
     $file = (array) json_decode($file);
     $value = html_entity_decode($value);
-    if ($file[$key] != $value) {
+    if (!isset($file[$key]) || $file[$key] != $value) {
         $file[$key] = $value;
         ksort($file);
         file_put_contents($filePath, str_replace('\/', '/', json_encode($file, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT)));
diff --git a/src/addon/block/onlineusers/onlineusers.scss b/src/addon/block/onlineusers/onlineusers.scss
index eb05cef2e..009a347b8 100644
--- a/src/addon/block/onlineusers/onlineusers.scss
+++ b/src/addon/block/onlineusers/onlineusers.scss
@@ -1,4 +1,12 @@
 .addon-block-online-users core-block-pre-rendered .core-block-content {
+    max-height: 200px;
+    overflow-y: auto;
+    .item-inner,
+    .input-wrapper {
+        overflow-y: visible;
+        align-self: start;
+    }
+
     .list {
         @include margin-horizontal(0);
         -webkit-padding-start: 0;
diff --git a/src/app/app.md.scss b/src/app/app.md.scss
index bee372275..a97ce6e95 100644
--- a/src/app/app.md.scss
+++ b/src/app/app.md.scss
@@ -70,6 +70,15 @@ ion-app.app-root.md {
       padding-top: 0;
       margin-top: $action-sheet-md-title-padding-top;
     }
+
+    @media (min-height: 500px) {
+      .action-sheet-wrapper {
+        bottom: 0;
+        top: initial;
+        max-height: 50%;
+        height: 100%;
+      }
+    }
   }
 }
 
diff --git a/src/app/app.scss b/src/app/app.scss
index 1118e0771..9fbf324f0 100644
--- a/src/app/app.scss
+++ b/src/app/app.scss
@@ -609,15 +609,6 @@ ion-app.app-root {
     }
   }
 
-  @media (min-height: 500px) {
-    .action-sheet-wrapper {
-      bottom: 0;
-      top: initial;
-      max-height: 50%;
-      height: 100%;
-    }
-  }
-
   .alert-message {
       overflow-y: auto;
   }
diff --git a/src/core/block/components/course-blocks/course-blocks.scss b/src/core/block/components/course-blocks/course-blocks.scss
index 61fcad7be..ef2da86c0 100644
--- a/src/core/block/components/course-blocks/course-blocks.scss
+++ b/src/core/block/components/course-blocks/course-blocks.scss
@@ -29,6 +29,17 @@ ion-app.app-root core-block-course-blocks {
                 min-width: $core-side-blocks-min-width;
                 @include border-start(1px, solid, $list-md-border-color);
             }
+
+            .core-course-blocks-content,
+            div.core-course-blocks-side {
+                position: relative;
+                height: 100%;
+
+                .core-loading-center,
+                core-loading.core-loading-loaded {
+                    position: initial;
+                }
+            }
         }
 
         @include media-breakpoint-down(sm) {
diff --git a/src/directives/external-content.ts b/src/directives/external-content.ts
index 94ebfcbcb..fac78ee17 100644
--- a/src/directives/external-content.ts
+++ b/src/directives/external-content.ts
@@ -50,6 +50,8 @@ export class CoreExternalContentDirective implements AfterViewInit, OnChanges {
     protected logger;
     protected initialized = false;
 
+    invalid = false;
+
     constructor(element: ElementRef, logger: CoreLoggerProvider, private filepoolProvider: CoreFilepoolProvider,
             private platform: Platform, private sitesProvider: CoreSitesProvider, private domUtils: CoreDomUtilsProvider,
             private urlUtils: CoreUrlUtilsProvider, private appProvider: CoreAppProvider, private utils: CoreUtilsProvider) {
@@ -142,6 +144,15 @@ export class CoreExternalContentDirective implements AfterViewInit, OnChanges {
             }
 
         } else {
+            this.invalid = true;
+
+            return;
+        }
+
+        // Avoid handling data url's.
+        if (url.indexOf('data:') === 0) {
+            this.invalid = true;
+
             return;
         }
 
diff --git a/src/directives/format-text.ts b/src/directives/format-text.ts
index 552ca9203..1335b31de 100644
--- a/src/directives/format-text.ts
+++ b/src/directives/format-text.ts
@@ -409,7 +409,12 @@ export class CoreFormatTextDirective implements OnChanges {
                 // Walk through the content to find images, and add our directive.
                 images.forEach((img: HTMLElement) => {
                     this.addMediaAdaptClass(img);
-                    externalImages.push(this.addExternalContent(img));
+
+                    const externalImage = this.addExternalContent(img);
+                    if (!externalImage.invalid) {
+                        externalImages.push(externalImage);
+                    }
+
                     if (this.utils.isTrueOrOne(this.adaptImg) && !img.classList.contains('icon')) {
                         this.adaptImage(img);
                     }
@@ -480,7 +485,9 @@ export class CoreFormatTextDirective implements OnChanges {
                 promise = Promise.resolve();
             }
 
-            return promise.then(() => {
+            return promise.catch(() => {
+                // Ignore errors. So content gets always shown.
+            }).then(() => {
                 return div;
             });
         });