WooCommerce login & Registration

I am making a small e-commerce website with Woocommerce. I have a problem about “Registration” and “Login” process.

First, I can register as a new customer. However, after hit the register button, it redirects to blog page, and the url of the page is

“example.com/theme/my-account/&aiowps_login_msg_id=session_expired” But the “Welcome” Email was sent to customer’s mail account.

After registration, when I try to log in as the same new customer, I cannot login the page. It also saying something like “Your account have to be activated by Administrator”. But I don’t know how to activate the account. The weird thing is I can log in as administrator.

If you know how to deal with this problem, please tell me anything. Thank you so much in advance.