PHP Fatal error: unlink() during syncing (PHP 8.0)

Hi!

I’m using the Theatre plugin (v0.18.3) in combination with the Stager (tickets) add-on (v2.2.2).

Now I’m not sure if it’s the base Theatre plugin or the add-on, but we’re getting a fatal error when trying to sync with Stager (either automatically or manually) when on PHP 8.0 or 8.1 (WordPress core is at 6.2.2).

When switching back to PHP 7.4, the sync is working.
Is the plugin PHP 8.0 compatible? Or is there. something else failing?

Please see the error below:

Uncaught TypeError: unlink(): Argument #1 ($filename) must be of type string, WP_Error given in /home/public_html/wp-content/plugins/theatre/functions/wpt_importer.php:808

Stack trace:
#0 /home/public_html/wp-content/plugins/theatre/functions/wpt_importer.php(808): unlink()
#1 /home/public_html/wp-content/plugins/mennolui-stager-for-theater-6d1c28f1b739/includes/wpt_stager_importer.php(330): WPT_Importer->update_production_thumbnail_from_url()
#2 /home/public_html/wp-content/plugins/theatre/functions/wpt_importer.php(868): WPT_Stager_Importer->process_feed()
#3 /home/public_html/wp-content/plugins/theatre/functions/wpt_importer.php(934): WPT_Importer->execute()
#4 /home/public_html/wp-includes/class-wp-hook.php(308): WPT_Importer->handle_import_linked()
#5 /home/public_html/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()
#6 /home/public_html/wp-includes/plugin.php(517): WP_Hook->do_action()
#7 /home/public_html/wp-settings.php(645): do_action()
#8 /home/public_html/wp-config.php(89): require_once('...')
#9 /home/public_html/wp-load.php(50): require_once('...')
#10 /home/public_html/wp-admin/admin.php(34): require_once('...')
#11 {main}
?thrown

Link to @unlink in line of code on Github: https://github.com/slimndap/wp-theatre/blob/v0.18.1/functions/wpt_importer.php#L808