diff --git a/src/app/lang.ts b/src/app/lang.ts
index 62fef5d..c61f566 100644
--- a/src/app/lang.ts
+++ b/src/app/lang.ts
@@ -98,6 +98,8 @@ export default function text(lang: string, input: string): string {
                     return "Überprüfe auf leere Eingabefelder...";
                 case "importing":
                     return "Importiere...";
+                case "err_invalidConstraintFormat":
+                    return "Fehler: Nicht erlaubter Operator verwendet.";
             default:
                 return input;
         }
@@ -203,6 +205,8 @@ export default function text(lang: string, input: string): string {
                 return "Checking for empty input boxes...";
             case "importing":
                 return "Importing...";
+            case "err_invalidConstraintFormat":
+                return "Error: Invalid constraint format.";
             default:
                 return input;
         }
diff --git a/src/app/scripts.ts b/src/app/scripts.ts
index 1894813..9d3ddcb 100644
--- a/src/app/scripts.ts
+++ b/src/app/scripts.ts
@@ -585,7 +585,7 @@ function parseLPConstraint(constraint: string): { vars: Variable[], bound: Bound
   const operators = ["<=", ">=", "="];
   let operator = operators.find(op => constraint.includes(op));
   if (!operator) {
-    throw new Error("Invalid constraint format");
+    throw new Error(getTranslation("err_invalidConstraintFormat"));
   }
 
   const [expr, boundStr] = constraint.split(operator);