The plugin causes issues when going through the "Lost your Password" process. Specifically, here's how to arrive at the error:
- Go to /wp-admin
- Click "Forgot your password?" link
- Enter email address, submit
- Red error message reads, "ERROR: The password field is empty." implying the plugin is trying to log you in using blank username/password fields. This error also occurs when clicking the confirmation link sent in the email.