Ticket #54906: 54906.diff

src/wp-admin/includes/upgrade.php

@@ -2273 +2273 @@
 
         if ( $wp_current_db_version < 51917 ) {
                 $crons = _get_cron_array();
-                // Remove errant `false` values, see #53950.
-                $crons = array_filter( $crons );
-                _set_cron_array( $crons );
+
+                if ( $crons && is_array( $crons ) ) {
+                        // Remove errant `false` values, see #53950.
+                        $crons = array_filter( $crons );
+                        _set_cron_array( $crons );
+                }
         }
 }