diff --git a/src/server.js b/src/server.js
index 102dc98..7e6283e 100644
--- a/src/server.js
+++ b/src/server.js
@@ -54,10 +54,24 @@ function getCalendarEntries(weekDate) {
 }
 
 async function getUntis(weekDate) {
-    const untisSchools = process.env.UNTIS_SCHOOLS.split(",");
-    const untisUsernames = process.env.UNTIS_USERNAMES.split(",");
-    const untisPasswords = process.env.UNTIS_PASSWORDS.split(",");
-    const untisServers = process.env.UNTIS_SERVERS.split(",");
+    let untisSchools = [];
+    let untisUsernames = [];
+    let untisPasswords = [];
+    let untisServers = [];
+    
+    let optionsSuccess = true;
+    try {
+        const untisSchools = process.env.UNTIS_SCHOOLS.split(",");
+        const untisUsernames = process.env.UNTIS_USERNAMES.split(",");
+        const untisPasswords = process.env.UNTIS_PASSWORDS.split(",");
+        const untisServers = process.env.UNTIS_SERVERS.split(",");
+    } catch (error) {
+        optionsSuccess = false;
+    }
+    
+    if (!optionsSuccess) {
+        return "Keine Untis-Optionen gefunden";
+    }
     
     let teachingContent = "";