diff --git a/core/bulkchange.class.inc.php b/core/bulkchange.class.inc.php
index 311ff5479..6ad8eb55c 100644
--- a/core/bulkchange.class.inc.php
+++ b/core/bulkchange.class.inc.php
@@ -160,7 +160,7 @@ class CellStatus_SearchIssue extends CellStatus_Issue
 	 * @param null $sAllowedValues : used for additional message that provides allowed values $sAllowedValues for current class
 	 * @param string|null $sAllowedValuesSearch : used to search all allowed values
 	 */
-	public function __construct($sSerializedSearch, $sReason, $sClass=null, $sAllowedValues=null, string $sAllowedValuesSearch=null)
+	public function __construct($sSerializedSearch, $sReason, $sClass = null, $sAllowedValues = null, string $sAllowedValuesSearch = null)
 	{
 		parent::__construct(null, null, $sReason);
 		$this->sSerializedSearch = $sSerializedSearch;
@@ -195,7 +195,7 @@ class CellStatus_SearchIssue extends CellStatus_Issue
 	public function GetSearchLinkUrl()
 	{
 		return sprintf("UI.php?operation=search&filter=%s",
-			rawurlencode($this->sSerializedSearch)
+			rawurlencode($this->sSerializedSearch ?? "")
 		);
 	}
 
@@ -206,7 +206,7 @@ class CellStatus_SearchIssue extends CellStatus_Issue
 	public function GetAllowedValuesLinkUrl(): ?string
 	{
 		return sprintf("UI.php?operation=search&filter=%s",
-			rawurlencode($this->sAllowedValuesSearch)
+			rawurlencode($this->sAllowedValuesSearch ?? "")
 		);
 	}
 }
@@ -262,7 +262,7 @@ class CellStatus_Ambiguous extends CellStatus_Issue
 	public function GetSearchLinkUrl()
 	{
 		return sprintf("UI.php?operation=search&filter=%s",
-			rawurlencode($this->sSerializedSearch)
+			rawurlencode($this->sSerializedSearch ?? "")
 		);
 	}
 }