diff --git a/app/admin/nat/edit.php b/app/admin/nat/edit.php
index 049ed9ded03b99972774a9bbe2a9f3a8e7ccc46d..f17756d3532979cc307e9c9823cf165770caa2b5 100644
--- a/app/admin/nat/edit.php
+++ b/app/admin/nat/edit.php
@@ -59,9 +59,9 @@ $custom = $Tools->fetch_custom_fields('nat');
     	<tr>
         	<th><?php print _('Name'); ?></th>
         	<td>
-            	<input type="text" class="form-control input-sm" name="name" value="<?php print $Tools->strip_xss(@$nat->name); ?>" placeholder='<?php print _('Name'); ?>' <?php print $readonly; ?>>
+            	<input type="text" class="form-control input-sm" name="name" value="<?php print $Tools->strip_xss($nat->name); ?>" placeholder='<?php print _('Name'); ?>' <?php print $readonly; ?>>
             	<input type="hidden" name="csrf_cookie" value="<?php print $csrf; ?>">
-            	<input type="hidden" name="id" value="<?php print @$nat->id; ?>">
+            	<input type="hidden" name="id" value="<?php print $nat->id; ?>">
             	<input type="hidden" name="action" value="<?php print escape_input($_POST['action']); ?>">
         	</td>
         	<td>
@@ -79,7 +79,7 @@ $custom = $Tools->fetch_custom_fields('nat');
             	<select name="type" class="form-control input-sm input-w-auto" <?php print $readonly; ?>>
                 <?php
                 foreach ($nat_types as $t) {
-                    $selected = @$nat->type==$t ? "selected" : "";
+                    $selected = $nat->type==$t ? "selected" : "";
                     print "<option value='$t' $selected>$t NAT</option>";
                 }
                 ?>
@@ -103,7 +103,7 @@ $custom = $Tools->fetch_custom_fields('nat');
                 <?php
                 if($devices !== false) {
                     foreach ($devices as $d) {
-                        $selected = @$nat->device==$d->id ? "selected" : "";
+                        $selected = $nat->device==$d->id ? "selected" : "";
                         print "<option value='$d->id' $selected>$d->hostname</option>";
                     }
                 }
@@ -119,7 +119,7 @@ $custom = $Tools->fetch_custom_fields('nat');
         <tr>
             <th><?php print _('Description'); ?></th>
             <td colspan="2">
-                <textarea class="form-control input-sm" name="description" placeholder='<?php print _('Port'); ?>' <?php print $readonly; ?>><?php print @$nat->description; ?></textarea>
+                <textarea class="form-control input-sm" name="description" placeholder='<?php print _('Port'); ?>' <?php print $readonly; ?>><?php print $nat->description; ?></textarea>
             </td>
         </tr>
 
@@ -133,7 +133,7 @@ $custom = $Tools->fetch_custom_fields('nat');
                 <select name="policy" class="form-control input-sm input-w-auto" <?php print $readonly; ?>>
                 <?php
                 foreach (["No", "Yes"] as $d) {
-                    $selected = @$nat->policy==$d ? "selected" : "";
+                    $selected = $nat->policy==$d ? "selected" : "";
                     print "<option value='$d' $selected>$d</option>";
                 }
                 ?>
@@ -144,12 +144,12 @@ $custom = $Tools->fetch_custom_fields('nat');
         </tr>
 
         <tr class='port'>
-            <th><?php print @$nat->type=="source" ? _('Destination address') : _('Source address'); ?></th>
+            <th><?php print $nat->type=="source" ? _('Destination address') : _('Source address'); ?></th>
             <td>
-                <input type="text" class="form-control input-sm" name="policy_dst" value="<?php print @$nat->policy_dst; ?>" placeholder='<?php print _('IP'); ?>' <?php print $readonly; ?>>
+                <input type="text" class="form-control input-sm" name="policy_dst" value="<?php print $nat->policy_dst; ?>" placeholder='<?php print _('IP'); ?>' <?php print $readonly; ?>>
             </td>
             <td>
-                <span class="text-muted"><?php print @$nat->type=="source" ? _('Destination') : _('Source'); print _(" address for policy NAT"); ?></span>
+                <span class="text-muted"><?php print $nat->type=="source" ? _('Destination') : _('Source'); print _(" address for policy NAT"); ?></span>
             </td>
         </tr>
 
@@ -157,11 +157,11 @@ $custom = $Tools->fetch_custom_fields('nat');
         	<td colspan="3"><hr></td>
     	</tr>
     	<tr>
-        	<th><?php print @$nat->type=="destination" ? _('Destination objects') : _('Source objects'); ?></th>
+        	<th><?php print $nat->type=="destination" ? _('Destination objects') : _('Source objects'); ?></th>
         	<td class='nat-src'>
             	<?php
                 // print sources
-                $sources = $Tools->translate_nat_objects_for_display (@$nat->src, @$nat->id, $link);
+                $sources = $Tools->translate_nat_objects_for_display ($nat->src, $nat->id, $link);
                 // sources
                 if($sources!==false) {
                     print implode("<br>", $sources);
@@ -180,7 +180,7 @@ $custom = $Tools->fetch_custom_fields('nat');
         	<th></th>
         	<td>
             	<?php
-                print "<hr><a class='btn btn-xs btn-success addNatItem' data-id='@$nat->id' data-type='src'><i class='fa fa-plus'></i></a> "._('Add new object');
+                print "<hr><a class='btn btn-xs btn-success addNatItem' data-id='$nat->id' data-type='src'><i class='fa fa-plus'></i></a> "._('Add new object');
                 ?>
         	</td>
         	<td>
@@ -198,7 +198,7 @@ $custom = $Tools->fetch_custom_fields('nat');
         	<td class='nat-dst'>
             	<?php
                 // print sources
-                $destinations = $Tools->translate_nat_objects_for_display (@$nat->dst, @$nat->id, $link);
+                $destinations = $Tools->translate_nat_objects_for_display ($nat->dst, $nat->id, $link);
                 // destinations
                 if($destinations!==false) {
                     print implode("<br>", $destinations);
@@ -217,7 +217,7 @@ $custom = $Tools->fetch_custom_fields('nat');
         	<th></th>
         	<td>
             	<?php
-                print "<hr><a class='btn btn-xs btn-success addNatItem' data-id='@$nat->id' data-type='dst'><i class='fa fa-plus'></i></a> "._('Add new object');
+                print "<hr><a class='btn btn-xs btn-success addNatItem' data-id='$nat->id' data-type='dst'><i class='fa fa-plus'></i></a> "._('Add new object');
                 ?>
         	</td>
         	<td>
@@ -233,7 +233,7 @@ $custom = $Tools->fetch_custom_fields('nat');
     	<tr class='port'>
         	<th><?php print _('Src Port'); ?></th>
         	<td>
-            	<input type="text" class="form-control input-sm" name="src_port" value="<?php print @$nat->src_port; ?>" placeholder='<?php print _('Port'); ?>' <?php print $readonly; ?>>
+            	<input type="text" class="form-control input-sm" name="src_port" value="<?php print $nat->src_port; ?>" placeholder='<?php print _('Port'); ?>' <?php print $readonly; ?>>
         	</td>
         	<td>
             	<span class="text-muted"><?php print _("Source port"); ?></span>
@@ -242,7 +242,7 @@ $custom = $Tools->fetch_custom_fields('nat');
     	<tr class='port'>
         	<th><?php print _('Dst Port'); ?></th>
         	<td>
-            	<input type="text" class="form-control input-sm" name="dst_port" value="<?php print @$nat->dst_port; ?>" placeholder='<?php print _('Port'); ?>' <?php print $readonly; ?>>
+            	<input type="text" class="form-control input-sm" name="dst_port" value="<?php print $nat->dst_port; ?>" placeholder='<?php print _('Port'); ?>' <?php print $readonly; ?>>
         	</td>
         	<td>
             	<span class="text-muted"><?php print _("Destination port"); ?></span>
diff --git a/app/admin/nat/item-add-search.php b/app/admin/nat/item-add-search.php
index 8d6348f9000ef2cf5d8c67ff9f507ad023b247ee..8efd8e4447fd77c04644b7b71c9e19c36f73d5b8 100644
--- a/app/admin/nat/item-add-search.php
+++ b/app/admin/nat/item-add-search.php
@@ -58,7 +58,7 @@ elseif($type == "IPv6") 	{ $search_term_edited = $Tools->reformat_IPv6_for_searc
 # search addresses
 $result_addresses = $Tools->search_addresses($search_term, $search_term_edited['high'], $search_term_edited['low'], array());
 # search subnets
-$result_subnets   = $Tools->search_subnets($search_term, $search_term_edited['high'], $search_term_edited['low'], $_REQUEST['ip']. array());
+$result_subnets   = $Tools->search_subnets($search_term, $search_term_edited['high'], $search_term_edited['low'], $_REQUEST['ip'], array());
 
 # if some found print
 if(sizeof($result_addresses)>0 || sizeof($result_subnets)>0) {
@@ -67,21 +67,31 @@ if(sizeof($result_addresses)>0 || sizeof($result_subnets)>0) {
     $html1 = [];
     $html2 = [];
 
+
     if(sizeof($result_subnets)>0) {
         $html1[] = "<h4>Subnets</h4>";
         foreach ($result_subnets as $s) {
-            if(!@in_array($s->id, $nat->src['subnets']) && !@in_array($s->id, $nat->dst['subnets']))
+            if(is_array($nat->src['subnets']) && is_array($nat->dst['subnets'])) {
+                if(!in_array($s->id, $nat->src['subnets']) && !in_array($s->id, $nat->dst['subnets'])) {
+                    $html1[] = "<a class='btn btn-xs btn-success addNatObjectFromSearch' data-id='".$_POST['id']."' data-object-id='$s->id' data-object-type='subnets' data-type='".$_POST['type']."'><i class='fa fa-plus'></i></a> ".$Tools->transform_address($s->subnet, "dotted")."/".$s->mask."<br>";
+                }
+            }
             $html1[] = "<a class='btn btn-xs btn-success addNatObjectFromSearch' data-id='".$_POST['id']."' data-object-id='$s->id' data-object-type='subnets' data-type='".$_POST['type']."'><i class='fa fa-plus'></i></a> ".$Tools->transform_address($s->subnet, "dotted")."/".$s->mask."<br>";
+
         }
-        if(sizeof($html1)==1) { $html1 = array(); }
+        if(sizeof($html1)==1) { $html1 = []; }
     }
     if(sizeof($result_addresses)>0) {
         $html2[] = "<h4>Addresses</h4>";
         foreach ($result_addresses as $a) {
-            if(!@in_array($a->id, $nat->src['ipaddresses']) && !@in_array($a->id, $nat->dst['ipaddresses']))
+            if(is_array($nat->src['ipaddresses']) && is_array($nat->dst['ipaddresses'])) {
+                if(!in_array($a->id, $nat->src['ipaddresses']) && !in_array($a->id, $nat->dst['ipaddresses'])) {
+                    $html2[] = "<a class='btn btn-xs btn-success addNatObjectFromSearch' data-id='".$_POST['id']."' data-object-id='$a->id' data-object-type='ipaddresses' data-type='".$_POST['type']."'><i class='fa fa-plus'></i></a> ".$Tools->transform_address($a->ip_addr, "dotted")."<br>";
+                }
+            }
             $html2[] = "<a class='btn btn-xs btn-success addNatObjectFromSearch' data-id='".$_POST['id']."' data-object-id='$a->id' data-object-type='ipaddresses' data-type='".$_POST['type']."'><i class='fa fa-plus'></i></a> ".$Tools->transform_address($a->ip_addr, "dotted")."<br>";
         }
-        if(sizeof($html2)==1) { $html2 = array(); }
+        if(sizeof($html2)==1) { $html2 = []; }
     }
     // print
     print implode("\n", $html1);
diff --git a/app/subnets/subnet-details/subnet-nat.php b/app/subnets/subnet-details/subnet-nat.php
index 51c4a3cbd89197207c7c70f33d447b032221994d..44eadf0010b9edeb226ca3e17128eacc38adb087 100644
--- a/app/subnets/subnet-details/subnet-nat.php
+++ b/app/subnets/subnet-details/subnet-nat.php
@@ -21,10 +21,12 @@ print "             <ul class='dropdown-menu'>";
                     $m=0;
                     foreach ($all_nats as $n) {
                         // not own
-                        if(!@in_array( $n->id, $all_nats_per_object['subnets'][$subnet['id']] )) {
-                            if($n->type=="source") {
-                                print "<li><a href='' class='mapNat' data-action='edit' data-id='$n->id' data-object-type='subnets' data-object-id='$subnet[id]'>$n->name ($n->type)</a></li>";
-                                $m++;
+                        if(is_array(@$all_nats_per_object['subnets'][$subnet['id']])) {
+                            if(!@in_array( $n->id, $all_nats_per_object['subnets'][$subnet['id']] )) {
+                                if($n->type=="source") {
+                                    print "<li><a href='' class='mapNat' data-action='edit' data-id='$n->id' data-object-type='subnets' data-object-id='$subnet[id]'>$n->name ($n->type)</a></li>";
+                                    $m++;
+                                }
                             }
                         }
                     }
diff --git a/misc/CHANGELOG b/misc/CHANGELOG
index 77c0f813a9dfb8047ff4368af3daf74ad5078515..a5137526bebbb2c06e4dff00b9056b932bde6c6b 100755
--- a/misc/CHANGELOG
+++ b/misc/CHANGELOG
@@ -11,6 +11,7 @@
     + Fixed php8 constructor fix for radius class (#3985);
     + Fixed Force mac address update during status update scan (#3791);
     + Fixed RADIUS authentication fails on 1.6.0 (#3986);
+    + Fixed cannot add NAT issue (#3993);
 
     Enhancements, changes:
     ----------------------------