6.8.1 Multisite: Uncaught TypeError: array_keys(): Argument #1 ($array) must be of type array, string given in wp-includes/class-wp-roles.php:291

[thejasonator]

I held off upgrading to 6.8 because of the multisite issue with older sites. I saw that bug was fixed in 6.8.1, but on upgrading I saw this error:

Fatal error: Uncaught TypeError: array_keys(): Argument #1 ($array) must be of type array, string given in /.../wp-includes/class-wp-roles.php:291
Stack trace:
#0 /.../wp-includes/class-wp-roles.php(291): array_keys()
#1 /.../wp-includes/class-wp-roles.php(332): WP_Roles->init_roles()
#2 /.../wp-includes/ms-blogs.php(707): WP_Roles->for_site()
#3 /.../wp-includes/class-wp-hook.php(326): wp_switch_roles_and_user()
#4 /.../wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#5 /.../wp-includes/plugin.php(517): WP_Hook->do_action()
#6 /.../wp-includes/ms-blogs.php(587): do_action()
#7 /.../wp-includes/admin-bar.php(685): switch_to_blog()
#8 /.../wp-includes/class-wp-hook.php(324): wp_admin_bar_my_sites_menu()
#9 /.../wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#10 /.../wp-includes/plugin.php(565): WP_Hook->do_action()
#11 /.../wp-includes/admin-bar.php(97): do_action_ref_array()
#12 /.../wp-includes/class-wp-hook.php(324): wp_admin_bar_render()
#13 /.../wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#14 /.../wp-includes/plugin.php(517): WP_Hook->do_action()
#15 /.../wp-admin/admin-header.php(277): do_action()
#16 /.../wp-admin/edit-form-blocks.php(376): require_once('...')
#17 /.../wp-admin/post.php(187): require('...')
#18 {main} thrown in /.../wp-includes/class-wp-roles.php on line 291

Strangely, the side admin bar renders, but the top admin bar doesn't.

[sabernhardt]

I'll move this to the "Role/Capability" component, but the issue involves switch_to_blog() in the toolbar's wp_admin_bar_my_sites_menu() function.

Do you find the error on any page (administration and/or front end), or is it only certain pages?

[SergeyBiryukov]

Hi there welcome to WordPress Trac!

The error message refers to the WP_Roles::$roles property, which should only ever be an array, but it appears to be changed to a string for some reason, most likely by a plugin or theme.

Does the issue still happens with all plugins disabled and a default theme (Twenty Twenty-Five) activated?

[SergeyBiryukov]

Could you also check the wp_user_roles option in the wp_options table? This error could also appear if that value is somehow corrupted.