PHP Fatal Error: Unable to update or view plugins while this theme is active

I am unable to update plugins or view them while this theme is active. Below are the php errors this theme is causing. please update the theme’s code so the errors are fixed.

The Error Code:

[19-Nov-2021 20:39:32 UTC] PHP Fatal error:  Uncaught Error: Cannot use object of type stdClass as array in /srv/htdocs/wp-content/themes/tropicana/functions.php:291
Stack trace:
#0 /wordpress/core/5.8.2/wp-includes/class-wp-hook.php(303): tropicana_admin_notice('')
#1 /wordpress/core/5.8.2/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array)
#2 /wordpress/core/5.8.2/wp-includes/plugin.php(470): WP_Hook->do_action(Array)
#3 /wordpress/core/5.8.2/wp-admin/admin-header.php(287): do_action('admin_notices')
#4 /wordpress/core/5.8.2/wp-admin/plugin-editor.php(154): require_once('/wordpress/core...')
#5 {main}
  thrown in /srv/htdocs/wp-content/themes/tropicana/functions.php on line 291