Unable to provide auditing information on alerts such as 

Which user closed out an alert on a particular job

WCC 11.4 SPx on ALL plateformes

To get the user who closed an Alert : 

In WCC ---> Configuration ---> Preferences --> Monitoring 

. add : modified_user in "Alert table Columns" 

. Save 

You will have the following alert information

alert,severity,status,job,server,create_time,status_time,modified_user