PHP Notice: Undefined index

Hi!

Thank you for this very usefull plugin.

Unfortunately our error log is cluttered with a PHP Notice which informs about the use of a none existent index in an array access.

[21-Apr-2026 11:39:25 UTC] PHP Notice: Undefined index: user_id_26 in /usr/www/xxxxxx/wp-content/plugins/custom-post-type-ui/inc/utility.php on line 1163

The code around this line is

1159 if ( $screen->base === 'edit' && ! empty( $_GET['post_type'] ) && in_array( $_GET['post_type'], $public, true ) ) {
1160         $dismissals = get_option( 'cptui-user-dismissed-extended-upsell', [] );
1161         if ( ! empty( $dismissals ) ) {
1162                 $user_id = get_current_user_id();
1163                 if ( 'true' === $dismissals[ 'user_id_' . $user_id ] ) {
1164                         return;
1165                 }
1166         }
             // ...
1172 }

The option value for option cptui-user-dismissed-extended-upsell is

a:1:{s:9:"user_id_8";s:4:"true";}

The user with id 26 is not part of the option array. Thus a PHP Notice is triggered when trying to access this none existing array element. A previous check for existence of the element is needed.

I would appreciate it if this can be solved with the next update.