Each Unity license seat allows activation on two machines simultaneously; activating on a third machine causes an error. To use a different machine, return an existing activation as explained in Unity's support article. For three or more simultaneous activations, purchase a new subscription under a separate Unity organization, which allows up to four activations per license key. ✨️
Cause:
Each Unity license seat can be active on two machines simultaneously. If you try to activate on a third machine while both activations are in use, the activation will be refused, and you will see an error message.
Resolution:
If you want to use either activation on a different machine, return the activation by following the steps in the article, How do I return the activations on my Pro/Industry/Enterprise license?.
If you require three or more activations at the same time, a new subscription must be purchased on a separate or new Unity organization. You can then assign another license (seat) to yourself or the affected user.
Note: License keys are generated per Unity ID. Providing a new subscription is purchased on a separate Unity organization from your existing subscription, the same license key will be valid for up to four activations.