Error when publishing a personal Workspace

[maieutiquer]

Q	A
Bug report?	yes
Version?	13.5.13

Steps:
Publish a workspace, then try unpublishing it

message:
"Call to a member function getId() on null"
class:
"Claroline\CoreBundle\Event\Log\LogResourcePublishEvent"
file:
"/var/www/html/claroline/src/plugin/notification/Manager/NotificationManager.php"
function:
"getExcludeUserIds"
line:
89