diff --git a/examples/simple.php b/examples/simple.php
index e1bfd9d..fe51fc2 100644
--- a/examples/simple.php
+++ b/examples/simple.php
@@ -1,5 +1,8 @@
 <?php
 
+ini_set("display_errors", true);
+error_reporting(-1);
+
 require_once "../vendor/autoload.php";
 
 use Itguild\Tables\Filter\InputDateFilter;
diff --git a/src/ListJsonTable.php b/src/ListJsonTable.php
index 5b6f8d1..38b00c9 100644
--- a/src/ListJsonTable.php
+++ b/src/ListJsonTable.php
@@ -229,7 +229,7 @@ class ListJsonTable extends JasonTable
                 }
             }
         }
-        if (is_array($this->beforePrintCell[$filter])) {
+        if (isset($this->beforePrintCell[$filter]) and is_array($this->beforePrintCell[$filter])) {
             if (isset($this->beforePrintCell[$filter]['filter'])) {
                 return true;
             }
@@ -268,9 +268,9 @@ class ListJsonTable extends JasonTable
             if ($this->issetFilter($key)){
                 $filter = $this->getCurrentFilter($key);
                 $class = new $filter['class']([
-                    'param' => $filter['param'],
+                    'param' => $filter['param'] ?? '',
                     'name' => $key,
-                    'value' => $filter['value']
+                    'value' => $filter['value'] ?? '',
                 ]);
                 $this->html .= $class->fetch();
             }