Question by DSimkin · Apr 05, 2017 at 08:02 PM · license 4.2

Get "Serial Expired" when activating an old version of Unity

I have Unity 5.3.4f1 (64-bit) Pro installed on my computer and working. I have just installed an older version of Unity (4.2.1), but when I try to activate the license I get an error "Serial expired". I believe I am using the same key for both versions of Unity. I was told by a co-worker that my license was upgraded to Unity 5. Does this mean I can no longer use Unity 4? It would be really helpful if I could still use Unity 4, so that I can patch old software released to customers.

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DSimkin · Apr 06, 2017 at 03:12 PM 0

I believe what I have is called a Unity 5 Pro perpetual license.

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DSimkin · Apr 06, 2017 at 07:45 PM 0

The following link says that Unity licenses are backwards compatible, so a Unity 5 license should in theory allow me to use Unity 4. Possibly this changed with the Unity 5 perpetual license??

https://support.unity3d.com/hc/en-us/articles/205056229-Can-my-license-work-on-previous-versions-of-Unity

DSimkin · Apr 10, 2017 at 03:11 PM 0

Now I am getting a different error message when I try to activate Unity 4. The new message is "Serial has reached the maximum number of activations. Disable existing activations to reuse this serial key." I tried booting up my old machine to deactivate old installations of Unity, but the two that still let me in appear to be deactivated already. The remaining installation complains about a conflict between machine id and serial key. I have contacted Unity support, and hopefully they can deactivate the remaining unused activation.