[Add New Users] Problem with add new users plugin

I am getting the following error and users are getting blank activation emails and nothing is coming up in phpmyadmin.
[20-Mar-2018 17:41:49 UTC] PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php:329
#0 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-includes/class-wp-hook.php(286): Add_New_Users->page_output('')
#3 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/admin.php(224): do_action('users_page_add-...')
#4 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/users.php(11): require_once('/homepages/18/d...')
thrown in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php on line 329
[20-Mar-2018 18:38:47 UTC] PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php:329
#0 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-includes/class-wp-hook.php(286): Add_New_Users->page_output('')
#3 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/admin.php(224): do_action('users_page_add-...')
#4 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/users.php(11): require_once('/homepages/18/d...')
thrown in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php on line 329
[20-Mar-2018 18:42:50 UTC] PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php:329
#0 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-includes/class-wp-hook.php(286): Add_New_Users->page_output('')
#3 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/admin.php(224): do_action('users_page_add-...')
#4 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/users.php(11): require_once('/homepages/18/d...')
thrown in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php on line 329
[20-Mar-2018 20:05:29 UTC] PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php:329
#0 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-includes/class-wp-hook.php(286): Add_New_Users->page_output('')
#3 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/admin.php(224): do_action('users_page_add-...')
#4 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/users.php(11): require_once('/homepages/18/d...')
thrown in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php on line 329
[22-Mar-2018 21:33:09 UTC] PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php:329
#0 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-includes/class-wp-hook.php(286): Add_New_Users->page_output('')
#3 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/admin.php(224): do_action('users_page_add-...')
#4 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/users.php(11): require_once('/homepages/18/d...')
thrown in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php on line 329
[22-Mar-2018 21:36:48 UTC] PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php:329
#0 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-includes/class-wp-hook.php(286): Add_New_Users->page_output('')
#3 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/admin.php(224): do_action('users_page_add-...')
#4 /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-admin/users.php(11): require_once('/homepages/18/d...')
thrown in /homepages/18/d278310800/htdocs/webapps/nhproduction/wp-content/plugins/add-new-users/add-new-users.php on line 329