--- a/client/src/components/Sidebar.vue	Tue Dec 17 14:27:44 2019 +0100
+++ b/client/src/components/Sidebar.vue	Tue Dec 17 15:05:56 2019 +0100
@@ -158,10 +158,14 @@
             }
           })
           .catch(error => {
-            const { status, data } = error.response;
+            let message = "Problems with backend";
+            if (error.response) {
+              const { status, data } = error.response;
+              message = `${status}: ${data.message || data}`;
+            }
             displayError({
-              title: "Backend Error",
-              message: `${status}: ${data.message || data}`
+              title: this.$gettext("Backend Error"),
+              message: message
             });
           });
       }