If PHP 7.x can not UNINSTALL then error:
php-fpm: error while loading shared libraries: libicuio.so.60
php-fpm: error while loading shared libraries: libonig.so.4
To fix above 2 error run these command then F5 aaPanel page, PHP74 will run again:
cd /root
wget http://security.ubuntu.com/ubuntu/pool/main/i/icu/libicu60_60.2-3ubuntu3.2_amd64.deb
apt install ./libicu60_60.2-3ubuntu3.2_amd64.deb
wget http://archive.ubuntu.com/ubuntu/pool/universe/libo/libonig/libonig4_6.7.0-1_amd64.deb
apt install ./libonig4_6.7.0-1_amd64.deb
If you PHP74 start with error "NOTICE: PHP message: PHP Warning: PHP Startup: Unable to load dynamic library 'zip.so' " then just F5 several times.