I have synth v studio pro on my daw machine.
I loaded the new Cakewalk Sonar beta version on a spare laptop to check it out and last night tried to install the 1.11b3 synthv. While it looks for all the world like synth V is going to work in the new Cakewalk Sonar, the license I attempted to supply said it was already used elsewhere - or something to that effect. It is, on my Daw machine in the basement. - I thought I could do this but have never tried.
Ron
I think it’s supposed to work, but maybe it’s some kind of bug with the beta version of the program?? After all, it is a beta.
IIRC, when I installed a copy of my studio pro on my laptop, for testing purposes, it seemed to be able to register A-OK, and I also was able to activate & deactivate copies of voices I bought. However I didn’t try a beta version out.
So I have a question/suggestion for you:
When you tried installing the beta to test out on your 2nd machine, did you already have a non-beta version installed on that machine? If not, maybe you gotta install the non beta version first. Because I’m p. sure that when you install the beta versions of Synth V, it keeps the stable versions installed, as opposed to overwriting them. So in my experience, whenever i’ve installed a beta version, I was installing it on a machine that already had a non-beta version installed and working just fine, and the process of installing the beta was more or less the same as a regular update to the program. (and you don’t need to RE-INPUT your activation codes every single update or anything, they should just be there already from last time)soooooo therefore maybe if you jump right from not-installed to installing the beta, it’s accidentally expecting an activation code specific to the beta vers, as opposed to the one u already have (for studio pro).
in other words I suggest you install the stable version of synthesizer v on the 2nd device, and check to see if that can activate properly. plus double check if you are copy+pasting the correct serial code &or the entire code(sometimes if its in an email, the code is really long and a couple characters are on the line below)
No, I went straight to the beta verion.
Thanks for your reply, tonight I will uninstall the beta and install the latest non beta copy and see if that will activate.
A quote from the Dreamtonics EULA:
Yeah, I knew I misinterprented it!
Thanks.
Don’t worry, you’re not the first one 
The three activations are meant for hardware changes, not for simultaneous use.
And the licencing of the voice databases is even more complicated, especially because we have several companies with different EULAs.
It’s too bad we can’t activate it on at leat 2 machines so I could monkey around with my songs on a laptop with my feet up and not be forced to be at the daw all the time.
I know I can deactivate the daw but that worries me too much to do that. 
Yes, but that would require a higher price, right? And I think the license is quite affordable … it’s bit more, than a new computer game.
I don’t play computer games. At all.
I had a software error on the plug-in in Logic and lost all my work. (Not a Logic fault/crash) all my tracks just suddenly vanished in SV while I was working.
I tried incremental recovery from an earlier version of the Logic file (SV data is saved in it) but it wasn’t there in any previous version I tried. So - I had to completely restore my MacBook Pro from Time Machine, using Migration Assistant… it took a few tries (different date/times) to find a previous version where the SV data was still in the project.
Long story short - Each time I restored the machine looking for a working file - I had to enter the activation code. By the time I found a working project to recover from the activations were all burned up apparently as I also got the error message - “This activation code is being used on another device".
I’m guessing a Time Machine each reinstallation is seen as a hardware change/new device.
I contacted Dreamtonics and they told me they won’t help because I bought it via DLSite.
Pretty awful non-support.
DLSite told me they wouldn’t help and to contact AH-Soft - so now I’m waiting on their response - but they are a distributor not the manufacturer so I’m not optimistic.
All I want to do is reset the counter on the activation for the same one computer I’ve only been using - and recover it. Hopefully someone can do this or the software glitch deletion of my data is going to cost me $90 to have to buy it all over again.
Thankfully I always save to an external SVP file, so I can edit standalone or in the DAW.
I’m shocked
PS: The license is saved in /Library/Application Support/Dreamtonics/Synthesizer V Studio/licence.bin … maybe you can recover a working license file from a Time Machine backup? Worth a try.