Error on saving

Hello,
I am on the settings page and on clicking save it generates the following errors
No other plugins are enabled and this is a fresh install.
Thanks
Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘boolval’ not found or invalid function name in /home/herrys18/public_html/wp-includes/class-wp-hook.php on line 288

Warning: Cannot modify header information – headers already sent by (output started at /home/herrys18/public_html/wp-includes/class-wp-hook.php:288) in /home/herrys18/public_html/wp-includes/pluggable.php on line 1216