There appears to be an issue with how SecurityAssist is creating the spry validation for confirm fields.
You can get rid of the error by finding where "undefined" is referenced in the spry script tag at the bottom of the page and update it to "none". However the confirm field still won't function properly.
To fix the confirm field validation entirely you would have to follow the steps outlined in this thread:
We have logged a bug on this issue and will get it fixed in the next update to avoid this inconvenience.