My registration email for ZBrush 4 contained this:
There has been a problem while processing your delivery. We are already working on this technical issue and may be waiting for information from the software publisher, which may cause short delay. At the latest, this should be solved within 1-2 workdays, although it is generally much less. We will contact you immediately via e-mail upon resolving the issue and apologize for any inconvenience.
I am also unable to login to the pixologic support site, as it gives this error:
ERROR: Domain does not match license key file domain (), please change the product path to match the domain under Admin CP > Settings > General Settings
This Product will not work properly unless untill that value is changed.
[WARNING]: Database Version Tag () and File (3.60.03) Mismatch!
At least the forums still work.