Hello,

You are allowed to activate the license up to 3 times on different domains so that if you develop the site on the staging platform, you could activate it on the final domain.

When you use the multisite you do not need additional licenses for each sub-domain.

If you activated the license three times earlier on the other domains and now are trying to activate on the forth you are getting this notice and you need to purchase a license.

One domain – one separate license.

Best Regards