boudie on "[Plugin: Login With Ajax] Error: ReflectionException thrown"

Hi,
I'm getting an error message after installing LWA version 3.1.2:

ReflectionException thrown
Function LoginWithAjax::shortcode() does not exist

I got this error when I wanted to create a new page on my site.
I'm running WP 3.8

http://wordpress.org/plugins/login-with-ajax/