I've wrote to support in December - never received an answer. My Sonar Professional + most products that shipped with it cannot be activated. Offline activation doesn't work, there's no error message.
 
Strange enough, the LP-Plugins that came with Sonar Pro, do work. Most of the other products don't, like the classic FX suite.
 
Activation Support on the Cakewalk Website now says "Under Construction", there's no way to contact Cakewalk.
 
What should I do?

Contact the new support group

Well I did try but Mr Scook beat me to it.

Occide, for the record Gibson dropped support and development of Cakewalk Software on the 17th of November 2017.  Consequently there was no one to answer you emails.

Have you tried contacting Bandlab support.  try filling in this form and explain your problem.

https://help.cakewalk.com/hc/en-us/requests/new
 

You've been waiting since December then three Hosts turn up at once....

Not by design Karyn.
 
I would first suggest the OP use the Cakewalk Command Center for activation if at all possible. Then consider upgrading to Cakewalk by BandLab. But this all depends on the OP's internet access.

Ok, thanks guys, I will try that. Strange enough, after writing this post I made another attempt of installing the "Nomad FX Suite" while Bandlab-Cakewalk was open in the background and this time it worked. I will try to continue like this, as long as the Plugins work with Bandlab I'm ok. :)