[2.7] PHP Warnings thrown in install pages tool

[gedex]

EXPLANATION OF THE ISSUE

When install pages through System status > Tools, PHP throws warnings:

[20-Feb-2017 09:10:30 UTC] PHP Warning:  Illegal string offset 'success' in /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-status.php on line 52
[20-Feb-2017 09:10:30 UTC] PHP Stack trace:
[20-Feb-2017 09:10:30 UTC] PHP   1. {main}() /srv/www/wc-e2e/htdocs/wp-admin/admin.php:0
[20-Feb-2017 09:10:30 UTC] PHP   2. do_action($tag = 'woocommerce_page_wc-status', $arg = *uninitialized*) /srv/www/wc-e2e/htdocs/wp-admin/admin.php:222
[20-Feb-2017 09:10:30 UTC] PHP   3. WP_Hook->do_action($args = array (0 => '')) /srv/www/wc-e2e/htdocs/wp-includes/plugin.php:453
[20-Feb-2017 09:10:30 UTC] PHP   4. WP_Hook->apply_filters($value = '', $args = array (0 => '')) /srv/www/wc-e2e/htdocs/wp-includes/class-wp-hook.php:323
[20-Feb-2017 09:10:30 UTC] PHP   5. WC_Admin_Menus->status_page('') /srv/www/wc-e2e/htdocs/wp-includes/class-wp-hook.php:298
[20-Feb-2017 09:10:30 UTC] PHP   6. WC_Admin_Status::output() /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-menus.php:218
[20-Feb-2017 09:10:30 UTC] PHP   7. include_once() /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-status.php:24
[20-Feb-2017 09:10:30 UTC] PHP   8. WC_Admin_Status::status_tools() /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/views/html-admin-page-status.php:32
[20-Feb-2017 09:10:30 UTC] PHP Warning:  Illegal string offset 'message' in /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-status.php on line 53
[20-Feb-2017 09:10:30 UTC] PHP Stack trace:
[20-Feb-2017 09:10:30 UTC] PHP   1. {main}() /srv/www/wc-e2e/htdocs/wp-admin/admin.php:0
[20-Feb-2017 09:10:30 UTC] PHP   2. do_action($tag = 'woocommerce_page_wc-status', $arg = *uninitialized*) /srv/www/wc-e2e/htdocs/wp-admin/admin.php:222
[20-Feb-2017 09:10:30 UTC] PHP   3. WP_Hook->do_action($args = array (0 => '')) /srv/www/wc-e2e/htdocs/wp-includes/plugin.php:453
[20-Feb-2017 09:10:30 UTC] PHP   4. WP_Hook->apply_filters($value = '', $args = array (0 => '')) /srv/www/wc-e2e/htdocs/wp-includes/class-wp-hook.php:323
[20-Feb-2017 09:10:30 UTC] PHP   5. WC_Admin_Menus->status_page('') /srv/www/wc-e2e/htdocs/wp-includes/class-wp-hook.php:298
[20-Feb-2017 09:10:30 UTC] PHP   6. WC_Admin_Status::output() /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-menus.php:218
[20-Feb-2017 09:10:30 UTC] PHP   7. include_once() /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-status.php:24
[20-Feb-2017 09:10:30 UTC] PHP   8. WC_Admin_Status::status_tools() /srv/www/wc-e2e/htdocs/wp-content/plugins/woocommerce/includes/admin/views/html-admin-page-status.php:32

STEPS TO REPRODUCE THE ISSUE

1. Checkout latest master
2. Activate plugin but skip wizard.
3. Install pages via System status > Tools