Cannot modify header information – headers already sent

As several other people have reported, my logs are filling up with:

[02-May-2025 06:37:09 UTC] Warning at www.shkspr.mobi/blog/wp-cron.php?doing_wp_cron: [2] Cannot modify header information - headers already sent in /shkspr.mobi/blog/wp-content/plugins/litespeed-cache/src/purge.cls.php on line 515

The specific line is part of the “Add tags to purge” function. Specifically:

// Send purge header immediately
$curr_built = $this->_build($purge2);
if (defined('LITESPEED_CLI')) {
        // Can't send, already has output, need to save and wait for next run
        self::update_option($purge2 ? self::DB_QUEUE2 : self::DB_QUEUE, $curr_built);
        self::debug('CLI request, queue stored: ' . $curr_built);
} else {
        @header($curr_built); // ← THIS LINE HERE!
        if (defined('DOING_CRON') || defined('LITESPEED_DID_send_headers') || apply_filters('litespeed_delay_purge', false)) {
                self::update_option($purge2 ? self::DB_QUEUE2 : self::DB_QUEUE, $curr_built);
                self::debug('Output existed, queue stored: ' . $curr_built);
        }
        self::debug($curr_built);
}

I can’t find a way to trigger it, so can’t easily test disabling all my plugins.

Any suggestions?

Last Report Number: HHHWIGVF

Last Report Date: 05/02/2025 12:52:50