Merge branch 'jupyterhub-share-base-staging' into 'jupyterhub-share-base-production'

Catch non existing backend service

See merge request jupyterjsc/k8s/config!326

static/js/home/dropdown-options.js

@@ -50,8 +50,8 @@ define(["jquery", "home/utils"], function (
     let systemFlavors = window.flavorInfo[system];
     if (!systemFlavors) {
       // Check if system should have flavor info but doesn't first
-      let backend = systemInfo[system].backendService;
-      if (backendInfo[backend].flavorsRequired || backendInfo[backend].userflavors) {
+      let backend = (systemInfo[system] || {}).backendService;
+      if (backend && (backendInfo[backend].flavorsRequired || backendInfo[backend].userflavors)) {
         // If so, we still want to create the flavor info to show the error message
         utils.createFlavorInfo(id, system);
         utils.setLabAsNA(id, "due to flavor");