Can't see login page after automatically update to 4.0

Hello,

I was working on 5-6 WordPress sites and there was no problem but form yesterday I can’t see my admin login page ex: https://beteasypromotions.com/wp-admin , https://beteasypromocode.net/wp-admin a blank page is coming – https://prntscr.com/4pjn1l

I am form Bangladesh but I have given this link to my friend who is in Australia; he can login without trouble!! No plugin used for prohibiting the users.

What’s the problem?