Can’t update user settings

When I try to update a users profile I get the following messages which I believe are coming from your plugin.

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘nxsUserProfileSettingsSave’ not found or invalid function name in /home/xxxxx/xxxx.xxx/wp-includes/class-wp-hook.php on line 300

Warning: Cannot modify header information – headers already sent by (output started at /home/xxxxx/xxxx.xxx/wp-includes/class-wp-hook.php:300) in /home/xxxxx/xxxx.xxx/wp-includes/pluggable.php on line 1195