diff --git a/application/utils.inc.php b/application/utils.inc.php
index 6bd953ab4..45656f2cc 100644
--- a/application/utils.inc.php
+++ b/application/utils.inc.php
@@ -1894,7 +1894,7 @@ class utils
 	 * (re)installation of iTop (especially during development). 
 	 * @return string
 	 */
-	public function GetCacheBusterTimestamp()
+	public static function GetCacheBusterTimestamp()
 	{
 		if(!defined('COMPILATION_TIMESTAMP'))
 		{
diff --git a/core/userrights.class.inc.php b/core/userrights.class.inc.php
index 5f56c5774..08dee7659 100644
--- a/core/userrights.class.inc.php
+++ b/core/userrights.class.inc.php
@@ -299,7 +299,7 @@ abstract class User extends cmdbAbstractObject
 		{
 			$oUser = UserRights::GetUserObject();
 			$oAddon = UserRights::GetModuleInstance();
-			if (method_exists($oAddon, 'GetUserOrgs'))
+			if (!is_null($oUser) && method_exists($oAddon, 'GetUserOrgs'))
 			{
 				$aOrgs = $oAddon->GetUserOrgs($oUser, '');
 				if (count($aOrgs) > 0)