Password error and custom registration login page

Hi,
I have a website with a custom theme which allows login and registration via a pop-up which comes in the link as #login or #register at end of URL. How do I setup the plugin to fit into this.
Also, the frontend registration page password entry gives “Your password must contain at least one lowercase letter, one capital letter and one number” error even though I have disabled strong password requirement in the plugin.
Please help.

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