Timeslip 2019 is not clearing Licenses


I am an IT Admin for a client who is using Timeslip as a daily basis. He only have 2 users. The timeslip version they are using is 2019. I am trying to clear 2 lincenses from the pc and/or server and having this issue that is not clearing the licenses. Can someone provide me some help or guide on this?

Thank You

Error that show when Clicking Clear All Licensing