server/AyaNova/biz/VendorBiz.cs

@@ -152,6 +152,10 @@ namespace AyaNova.Biz
                 try
                 {
                     Vendor dbObject = await ct.Vendor.SingleOrDefaultAsync(z => z.Id == id);
+                     if (dbObject == null){
+                        AddError(ApiErrorCode.NOT_FOUND);
+                        return false;
+                    }
                     ValidateCanDelete(dbObject);
                     if (HasErrors)
                         return false;