For your security, your password needs to be strong.
If your password is too weak, the you will not be able to register.
Tip: Your password should be at least twelve characters long. To make it stronger, use upper and lower case letters, numbers, and symbols like ! " ? $ % ^ & ).
EXAMPLE 1
Password too weak - REGISTER button is not active.
EXAMPLE 2
Password ok - the REGISTER button is active