When a user comes to the site (strw.us) and clicks the reset password link it pops up the screen that allows the user to provide their email address.  If the user is logged on the email is sent - it is a beautiful email.  However if the user is not logged on then when they press the button after providing their email address they get a white box with a wordpress error saying:

There has been a critical error on your website.

Learn more about debugging in WordPress.

The link in a ninja form that is at the top of my home page unst under the header

it takes the user to a /set-your-password/ page which has only the one shortcode [reset_password]

Any help is greatly appreciated