Report Error on status page if content page returns error

assets/page.erb

@@ -164,9 +164,13 @@
     fetch("?content", { credentials: "same-origin" })
       .then(function(response) {
         if (response.ok) return response.text();
+        throw new Error();
       })
       .then(function(html) {
-        if (html) document.getElementById("content").innerHTML = html;
+        document.getElementById("content").innerHTML = html;
+      })
+      .catch(function() {
+        document.getElementById("content").innerHTML = "Error";
       });
   </script>
 <% end %>