PHP error when register

When a user attempts to register the following errors are thrown:

Warning: call_user_func_array() expects parameter 1 to be a valid callback, array must have exactly two members in /home4/hardhat/public_html/freetrainingidaho.com/wp-includes/plugin.php on line 235

Fatal error: Call to a member function get_error_code() on a non-object in /home4/hardhat/public_html/freetrainingidaho.com/wp-includes/user.php on line 2311