Please try to update composer package:
cd playsms-1.4.5
php composer.phar update
Above composer update will update playsms-1.4.5/web/lib/composer files.
Once done copy folder playsms-1.4.5/web/lib/composer to your playSMS installation folder to replace them with the new updated one, same path (to your-playsms-web-path/lib/composer).
If you’re still using playSMS 1.4.3 then you can also replace all your playSMS 1.4.3 PHP files (except config.php) with the updated files in playsms-1.4.5/web/
anton