As the owner of an MV account/site, you should always be using the Admin Login Page to access your account.
Your Admin Login Page is found by adding '/admin' to your MV site's link as shown in this example:
From this page, you can also reset your admin password should you have forgotten it. Resetting your admin password can only be done on this page.
You can also access your admin login page from the general sign-in area on your site's main page by clicking 'Sign-In' and then clicking the 'admin login' prompt if you have it visible (It is set to visible by default).
Note that if you don't want to display the 'admin login' link in the general sign-in area, you can turn it off by clicking on Settings -> General, and setting the Show "admin login" on Login Form dropdown to 'No':
If you aren't sure what your account link is, you can look it up here: https://membervault.co/lookup
Questions? Reach out to us at hello@membervault.co, via chat support within your Admin account, or connect with other users within our FB Group, The MV Collaborative.