The most common problem is an incorrect User ID or License Code. Your User ID is the full name you used when purchasing the MacHeist Bundle, not your email address. The User ID, number of Copies, and License Code must be entered exactly as shown in the email; please don't abbreviate. You can enter this information by simply copying and pasting it directly into the registration window.
If you have attempted to enter your registration information more than 3-4 times and are still receiving an "Invalid error", please relaunch the application. Too many failed registration attempts will cause the software to reject your License Code.