diff --git a/resources/js/event_billing.js b/resources/js/event_billing.js
index 6c6790c..da5cb9a 100644
--- a/resources/js/event_billing.js
+++ b/resources/js/event_billing.js
@@ -71,10 +71,12 @@ EventBilling = (function () {
         if (event.state >= 7) {
             $(".progress_personnel_billing").addClass("active");
 
-            for (let state of billing_states) {
-                $(".progress_approve_" + state.entity_id).addClass("active");
-                if (state.entity_id === event_min_billing_state) {
-                    break;
+            if(event_min_billing_state) {
+                for (let state of billing_states) {
+                    $(".progress_approve_" + state.entity_id).addClass("active");
+                    if (state.entity_id === event_min_billing_state) {
+                        break;
+                    }
                 }
             }
         }
@@ -94,7 +96,7 @@ EventBilling = (function () {
         }
     };
     let load_min_billing_states_for_event = async function (event_id) {
-        const res = $.ajax({
+        const res = await $.ajax({
             url: '/api/events/' + event_id + '/billing_states/min',
             type: 'GET',
             contentType: 'application/json',
@@ -103,7 +105,9 @@ EventBilling = (function () {
                 alert("Es ist ein Fehler aufgetreten!");
             }
         });
-        if (is_ok(res)) {
+        if('error' in res){
+            return null;
+        }else{
             return res;
         }
     };