Fix additional edge case for the sideBySideFullscreen=false + status=false bug

src/js/easymde.js

@@ -883,10 +883,12 @@ function toggleSideBySide(editor) {
     }
 
     function removeNoFullscreenClass(el) {
+        if (el != null) {
             el.className = el.className.replace(
                 /\s*sided--no-fullscreen\s*/g, ''
             );
         }
+    }
 
     if (/editor-preview-active-side/.test(preview.className)) {
         if (cm.getOption('sideBySideNoFullscreen')) {
@@ -909,9 +911,9 @@ function toggleSideBySide(editor) {
                 if (editor.options.sideBySideFullscreen === false) {
                     cm.setOption('sideBySideNoFullscreen', true);
                     noFullscreenItems.forEach(function(el) {
-                        if (el) {
+                        if (el != null) {
                             addNoFullscreenClass(el);
-                        };
+                        }
                     });
                 } else {
                     toggleFullScreen(editor);