This is without a doubt the most common problem, so I will be making a video on how to do this.
Please follow the instructions in the help section of the software AND on the paper the is supplied.
There are
2 keys.
1) Software Key (This is NOT on the paper, and needs to be requested to activate your software).
2) NEMU KEY - This is on the paper that is supplied with your ECU and can be entered once the software is activated by the user!
Check this link for how to register your software.
NismoTronic Help - Software Registration