I have just updated/installed a new Operating System. Why is my license failing to activate?


  • I have just installed Windows 10 on my computer.
  • I just updated my Operating System
  • On opening Unity, I receive an error and it will not activate.


Unfortunately, sometimes our licenses are confused by a change in OS - essentially, it tricks the license file into thinking it is being activated on a new machine, which can cause problems if you have already maxed out your activations.


Please follow this process:

1) Uninstall Unity

2) Delete this file:

* Windows: C:ProgramData/Unity (If the files are hidden, you need to click View and tick the Hidden Items check box.)

* Mac: Library/Application Support/Unity

3) Restart

4) Download Unity again from our website

5) Reinstall, remembering to select ‘activate free version’ when prompted for Personal, or enter your serial number for Plus or Pro.


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  • 0

    It was enough to delete the license file *.ulf, then activate free, run unity, and activate pro/plus (license check still hanged, but you can close it)

  • 0
    Sergio Carneiro

    I'm using Windows 10 and this happened after an update.

    I tried everything and more than everything, nothing worked, the only solution I got was to revert the update. This is easily done in the "Recovery" settings.

  • -1

    Hi Sergio,

    If you have a Plus or Pro license activated on your machine, it may be that you need to return this activation in order to activate on your new OS version.

    You can return your activations when logged in at and under the 'My Seats' tab. Alternatively, you can return them from within the Unity Editor.

    - Click 'Help'

    - Click 'Manage License'

    - Click 'Return License'

  • 0
    Unity Builds 4

    Is there a programmatic way to free our licenses? Having to manually sign into the webpage is a problem. Do you have a web API that we could use to release/return licenses?

  • 0

    Hi there,

    We do have some command line arguements to release licenses which you may find useful:

  • 2
    Paul Bronowski

    This will do the trick...

    - Close Unity and Unity Hub app
    start cmd.exe as admin
    for /f %i in ('tlist ^| findstr /i unity') do (kill -f %i)

    - Delete (or back up) the local license cache files
    C:\ProgramData\Unity>del *.ulf

    - Delete any appropriate activations on the service side

     - Restart Unity Hub app. Provide product key. The last button will be "Install Unity", which is misleading - you already have Unity installed. It's should just be a success message with a Continue button. Clicking it will take you home.

    - Keep calm and go about your business. ;)

    Edited by Paul Bronowski
  • 0

    Sorry not working for me. Also you should update this page as it is not saying anything about Unity Hub which is actually managing the licenses. I have contacted support now, as I am not able to solve the problem.

  • 4
    Andre Weinhold

    I had the same problem the last two days. The following worked:

    Please go to:

    And remove _all_ assigned values. Then Activate again with Serial etc. in Unity Hub.

  • 1

    Problem solved if you are using unity hub(i am using unity hub 2.1.0) to manage your unity license!

    First, delete  C:\ProgramData\Unity.

    Then, remove all activated device values in your unity ID site(My Account->My Seats) 

    Finally, restart system and enter your serial number in unity hub.


    Edited by 邓中洋
  • 1
    Tony Topper

    Not happy with this solution.  Time is precious.  Do a better job please.

  • 0

    Well, this wasted a few hours of my life... After uninstalling, reinstalling, Unity Hub showing it had the license but it still not appearing in the editor.

    On another support page, I discovered I had to go to 

    There, I could see there were two old activations which needed to be deactivated (likely from a previous purchase years ago)


    ... then follow the directions on this page to clear ProgramData and only Unity Hub could correctly acquire the license and I could see that reflected in the editor.

    Unity: Fix your licensing, I agree with Tony, time is precious.

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