Login not working / login page

It looks like you’ve got a login captcha included. Keep in mind that while WP-Members does include the WP hooks to include that, not all plugins that apply additional authentication include their scripts fully on the front end. Some only test for wp-login.php and may or may not work on front end logins. While WP-Members includes the necessary hooks for compatibility, that ultimately depends on the other plugin.

I would recommend disabling whatever additional authentication you have for login (i.e. captcha or otherwise) and retesting.