diff --git a/Webshop.Application/DTOs/Products/UpdateAdminProductDto.cs b/Webshop.Application/DTOs/Products/UpdateAdminProductDto.cs
index e303c2f..6f56787 100644
--- a/Webshop.Application/DTOs/Products/UpdateAdminProductDto.cs
+++ b/Webshop.Application/DTOs/Products/UpdateAdminProductDto.cs
@@ -36,6 +36,6 @@ namespace Webshop.Application.DTOs.Products
         public bool IsFeatured { get; set; }
         public int FeaturedDisplayOrder { get; set; }
 
-        public byte[]? RowVersion { get; set; }
+        public string? RowVersion { get; set; }
     }
 }
\ No newline at end of file
diff --git a/Webshop.Application/Services/Admin/AdminProductService.cs b/Webshop.Application/Services/Admin/AdminProductService.cs
index 6a096de..1678c0a 100644
--- a/Webshop.Application/Services/Admin/AdminProductService.cs
+++ b/Webshop.Application/Services/Admin/AdminProductService.cs
@@ -120,12 +120,39 @@ namespace Webshop.Application.Services.Admin
                 return ServiceResult.Fail(ServiceResultType.NotFound, $"Produkt mit ID '{productDto.Id}' nicht gefunden.");
             }
 
-            // SCHRITT 2: Setze SOFORT den Concurrency Token am "sauberen" Objekt.
-            if (productDto.RowVersion != null && productDto.RowVersion.Length > 0)
+            // --- CONCURRENCY CHECK ---
+            if (!string.IsNullOrEmpty(productDto.RowVersion))
             {
-                _context.Entry(existingProduct).Property(p => p.RowVersion).OriginalValue = productDto.RowVersion;
+                try
+                {
+                    // <<<<<< WICHTIGE KORREKTUR HIER >>>>>>
+                    // FormData wandelt "+" oft in " " um. Das reparieren wir hier:
+                    string fixedRowVersion = productDto.RowVersion.Replace(" ", "+");
+
+                    // 1. Umwandlung von String (Base64) zu Byte-Array
+                    byte[] incomingRowVersion = Convert.FromBase64String(fixedRowVersion);
+
+                    // DEBUG-LOGGING
+                    string dbValue = Convert.ToBase64String(existingProduct.RowVersion ?? new byte[0]);
+
+                    Console.WriteLine($"DB RowVersion:       {dbValue}");
+                    Console.WriteLine($"Frontend RowVersion: {fixedRowVersion}"); // Logge den reparierten Wert
+
+                    if (dbValue != fixedRowVersion)
+                    {
+                        Console.WriteLine("!!! WARNUNG: Versionen stimmen nicht überein !!!");
+                    }
+
+                    // 2. Setze den Originalwert für EF Core
+                    _context.Entry(existingProduct).Property(p => p.RowVersion).OriginalValue = incomingRowVersion;
+                }
+                catch (FormatException)
+                {
+                    return ServiceResult.Fail(ServiceResultType.Failure, "RowVersion Format ist ungültig.");
+                }
             }
 
+
             // SCHRITT 3: Lade jetzt die Relationen explizit nach.
             await _context.Entry(existingProduct).Collection(p => p.Images).LoadAsync();
             await _context.Entry(existingProduct).Collection(p => p.Productcategories).LoadAsync();