Why have I lost my second ZBrush activation?

• Pixologic allowed multiple activations of a single license, which was meant to allow one user to swap between machines (such as home and office, or PC and laptop) but was not for concurrent use, as per their FAQ : Can I install my software on more than one computer? 
  
  
• With MyMaxon ZBrush licenses, the software can be installed on as many machines as is required and the license transferred to the machine that you wish to work on.

For more information, visit: How do I use my license on a different computer?