Checkbox not working.

2 checkbox is working but This 3 Checkbox Can’t working. please tell me how can I fix it.

I can’t understand this logic. please Solve this logic. how can I Added Lower Case + Upper case + and Number text Random generate.

i think you cant use 3rd and, and in each number list you must have to use from 1 to length of list of any list which you use, you cant use text box instead of list, like my blocks of my project