Does my license work on previous versions of Unity?

Symptoms

• I have a Pro license and I am trying to activate Unity in a different version.
• I would like to know which versions of Unity I can activate with the license I have.
• I would like to know if I can activate my license on previous versions of Unity.
• I am receiving this error: “Serial is not valid for the requested version of Unity.”

Cause

Depending on the license type you have, Unity licenses are generally backwards compatible. This means that for each license version, you can activate all versions prior to that release, but not newer versions.

For example, if you have a Unity 4.x license, you can activate any version of Unity 4, or Unity 3. Unity 5.x licenses can be activated in all versions of Unity 5, 4 and 3.

If you currently have an active subscription, you will have the most up to date license which can be used on any version. 

Pay-to-Own licenses are tied to the most recent, stable version of the Editor when the license was converted. These licenses are backwards compatible on all prior versions except LTS (Long Term Support) versions of the Editor.

Resolution

If you have an old license and would like to activate on a newer version, you will need to upgrade your license. You can do this through the Unity website, or through contacting your Sales rep using the information here.

To use an older version of Unity, you can download the version you are looking for here.

More Information

Generally, subscription licenses can be used on all currently released versions of Unity.  If your license isn’t working on an expected version, please reach out to support.