diff --git a/app.ts b/app.ts
index c102ad7..e6d9b05 100644
--- a/app.ts
+++ b/app.ts
@@ -29,8 +29,7 @@ app.use(express.json());
 // Configure CORS
 let allowedHosts = [
 	'https://www.nachklang.art',
-	'https://calendar.nachklang.art',
-	'http://localhost:4200'
+	'https://calendar.nachklang.art'
 ];
 app.use(cors({
 	origin: function (origin: any, callback: any) {
diff --git a/src/models/calendar/events/events.router.ts b/src/models/calendar/events/events.router.ts
index 93482bc..f562bde 100644
--- a/src/models/calendar/events/events.router.ts
+++ b/src/models/calendar/events/events.router.ts
@@ -123,7 +123,8 @@ eventsRouter.post('/', async (req: Request, res: Response) => {
 			req.body.calendarId === undefined ||
 			isNullOrBlank(req.body.name) ||
 			req.body.startDateTime === undefined ||
-			req.body.endDateTime === undefined
+			req.body.endDateTime === undefined ||
+			isNullOrBlank(req.body.createdBy)
 		) {
 			res.status(400).send({'message': 'Required parameters missing'});
 			return;
@@ -172,7 +173,8 @@ eventsRouter.put('/:eventId', async (req: Request, res: Response) => {
 			req.body.calendarId === undefined ||
 			isNullOrBlank(req.body.name) ||
 			req.body.startDateTime === undefined ||
-			req.body.endDateTime === undefined
+			req.body.endDateTime === undefined ||
+			isNullOrBlank(req.body.createdBy)
 		) {
 			res.status(400).send({'message': 'Required parameters missing'});
 			return;