Blocs activation only on one device?

[Creative]

I am needing to use Blocs on 2 devices; An iMac and a Macbook Pro. When I use one, I get a message on the other that I’ll need to enter an activation code. When I do that, then it deactivates Blocs on the other. Can I not use Blocs on 2 devices?

PS: Why won’t it display my screenshot here?

[Flashman]

You can use Blocs on a hundred computers, just not at the same time.

The non showing images is a longstanding forum issue that is very random. At time of writing I can see the image.