Getting these errors when running debug to get a contact form to work…

This plugin has worked great for me for quite some time now. I only found these following PHP Notices after running the Debug plugin to get a newly installed Contact Form to work.

These show as being repeated several times in a row before the end of the error log.

What do I need to do to fix these errors?

[12-Jun-2015 12:51:06 UTC] PHP Strict standards:  Declaration of PG_Walker_Nav_Menu_Edit_Custom::start_lvl() should be compatible with Walker_Nav_Menu::start_lvl(&$output, $depth = 0, $args = Array) in C:\wamp\www\roadworksmfg\wp-content\plugins\private-content\pg_nav_menu_option.php on line 285

[12-Jun-2015 12:51:06 UTC] PHP Strict standards:  Declaration of PG_Walker_Nav_Menu_Edit_Custom::end_lvl() should be compatible with Walker_Nav_Menu::end_lvl(&$output, $depth = 0, $args = Array) in C:\wamp\www\roadworksmfg\wp-content\plugins\private-content\pg_nav_menu_option.php on line 285

[12-Jun-2015 12:51:06 UTC] PHP Strict standards:  Declaration of PG_Walker_Nav_Menu_Edit_Custom::start_el() should be compatible with Walker_Nav_Menu::start_el(&$output, $item, $depth = 0, $args = Array, $id = 0) in C:\wamp\www\roadworksmfg\wp-content\plugins\private-content\pg_nav_menu_option.php on line 285

Thanks!

https://wordpress.org/plugins/private-content/