WP Customer Reviews Pagination and Form Submit only works when logged in to admin

Whenever I log out of WordPress admin area pagination and form submit do throw a "An unknown error has occurred. E01".

Pagination does not work at all. The form submit does submit but still throws an error.

When I am logged in the plugin works perfectly. I am using a custom theme.

Plugin: http://ift.tt/1uxTs9u

Issue Page: http://ift.tt/1MFxAqH

via Chebli Mohamed