Warnings in editor page

In back end post editor I found these warnings:

Warning: array_unshift() expects parameter 1 to be array, null given in /web/htdocs/www.www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/post-format-ui.php on line 200

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 21

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 21

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 21

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 21

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 21

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 21

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 46

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 46

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 46

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 46

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 46

Warning: in_array() expects parameter 2 to be array, null given in /web/htdocs/www.domainname.com/home/wp-content/plugins/grid-plus/core/post-format-ui/templates/tabs.php on line 46

WORDPRESS: 4.8
PHP INFO: 5.5.38 | SAPI: cgi-fcgi
SERVER: Apache
PHP TIME LIMIT: (0) no time limit imposed
PHP MAX MEMORY: 2048M (256M default)
MEMORY STACK: 45MB

MySQL
Version 5.6.35
Comments Percona Server (GPL), Release 81.0, Revision c96c427
Charset utf8mb4

Gantry 5.4.13 framework

Thanks!