Issue:
php7.2 bin/magento theme:uninstall frontend/Smartwave/porto_rtl
Error: frontend/Smartwave/porto_rtl is not an installed Composer package
Let us delete it manually:
Run the following query:
DELETE from theme where theme_path='Smartwave/porto_rtl';
Open shell and change directory to your vhost:
cd /var/www/domain.com/web
Run:
mv app/design/frontend/Smartwave/porto_rtl /root/;
rm -rf var/view_preprocessed pub/static/frontend;
php7.2 bin/magento cache:clean;
php7.2 bin/magento cache:flush;
php7.2 bin/magento setup:static-content:deploy --theme Magento/backend nl_NL en_US;
php7.2 bin/magento setup:static-content:deploy --theme Smartwave/porto nl_NL en_US;