Technical Issue Painter Essentials 5

Hello, 

I received the Intuos Art Wacom Tablet with the free art pack. 

I installed all the necessary for the tablet and have seen that the tablet works fine.

My problem is that when I install Painter Essentials 5 it asks me for a serial number. At first i entered the tablet one but it told me that it was wrong so i proceeded to open it without it. Unfortunately, when I opened it it would freeze with the logo of the app in the center. i had to Force Quit otherwise the logo would remain in the center of the screen even if I wanted to use other applications.

I was wondering where I can find the serial number. 

Don't know if it makes any difference but i live in Italy, but the tablet, i believe, was also bought in Italy so i don't think that should create a problem.

Thank you in advance.