Sermons List fails to sort by heading

After upgrading to Sermonspeaker 7 (Joomla 6), the Sermons List page fails to sort when clicking on headings eg Date or Title. The error message is as follows:0Sermonspeaker\Plugin\Sermonspeaker\Mediaelement\Extension\Mediaelement::createSource(): Argument #2 ($file) must be of type string, null given, called in /home/therefor/public_html/plugins/sermonspeaker/mediaelement/Extension/Mediaelement.php on line 171

Any help solviing this issue would be greatly appreciated, thx!

Thanks for the report. I have found the issue and released an update for the mediaelement plugin.
You should see the update to 7.0.1 in your backend.