diff -u b/core/modules/contextual/js/contextual.js b/core/modules/contextual/js/contextual.js
--- b/core/modules/contextual/js/contextual.js
+++ b/core/modules/contextual/js/contextual.js
@@ -163,7 +163,7 @@
       // Update all contextual links placeholders whose HTML is cached.
       var uncachedIDs = _.filter(ids, function initIfCached(contextualID) {
         var html = storage.getItem('Drupal.contextual.' + contextualID);
-        if (typeof html === 'string' && html.length > 0) {
+        if (html && html.length) {
           // Initialize after the current execution cycle, to make the AJAX
           // request for retrieving the uncached contextual links as soon as
           // possible, but also to ensure that other Drupal behaviors have had
@@ -192,7 +192,7 @@
               // If the rendered contextual links are empty, then the current
               // user does not have permission to access the associated links:
               // don't render anything.
-              if (html.length > 0) {
+              if (html && html.length) {
                 // Update the placeholders to contain its rendered contextual
                 // links. Usually there will only be one placeholder, but it's
                 // possible for multiple identical placeholders exist on the