If both the users are different then you must click on th X sign at the right hand side.
Once you click the license will be qurantine for 24 hours. After 24 Hour the license will be free and you can assign to other user.
If the users are same then you must change the display name property in Active Directory from where you are getting the user name. QlikView can not change the display name
Regards,
Kaushik Solanki
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