Hi there!

Sorry for the inconvenience!

Please enter to your template folder then go to this location \administrator\components\com_splms\models\lesson.php

Replace the current line with the fixed line: https://prnt.sc/sr7hm7

Current line 141:

$media_file = pregreplace("/[\s-]+/", "-", JFile::makeSafe(basename(strtolower($name)))); (working for PHP 7.2 and below)

fixed line 141:

$media_file = pregreplace("/[\s-]+/", "-", JFile::makeSafe(basename(strtolower($name)))); (working for PHP 7.3 and higher)

Hope this helps!

Best Regards