TH2 works without a serial number but TH3 seems to require one. The only thing that seems to be available is a limited demo.
I tried going on Overloud's web page but cannot find anyway to authorize the Cakewalk version. Would seem that it should be automatically licensed if available from Cakewalk as a download. Sorry but I can't seem to figure it out without some help.
Thanks for any response.
 

TH3 Cakewalk works without any additional authorization. Unlike TH2 Creator/SONAR/Producer, TH3 Cakewalk has the full version and demo built into the plug-in but these are not necessary to activate to use TH3 Cakewalk.

Scook, when I open TH3 there are greyed-out presets that when I select they asked for authorization. If I unselect view all then I see specific Cakewalk presets that are available without authorization. Is that the way it is suppose to work?

I believe so. TH3 Cakewalk is a lite version of TH3 just like versions of TH2 bundled with previous Cakewalk DAWs. As mentioned above one difference is TH3 Cakewalk also contains demo and full versions. The greyed-out presets are part of the demo and full versions.

 I pretty much have been sticking with Guitar Rig 5 Pro for several years, esp since I got my hands on a Kontrol Rig 3. But as TH3 has come out I have been relooking at Overloud's option again. I hated the UI of TH2, but I think I can get used to the changes in TH3.
I do notice a huge increase in signal strength in both Overloud amp sims over the Guitar Rig...anyone else.l experiencing this?
 
This is huge when using as a stand alone for live playing with my audio interface's output going into my Fender amp effects return.