There are 3 ways to fix it.

1. Go to WHM >> Server Configuration >> Tweak Setting and choose ioncube on 'Loader to use for internal cPanel PHP'. Then check your RVSitebuilder again.

2. run

perl /var/cpanel/rvglobalsoft/rvsitebuilder/panelmenus/cpanel/scripts/autofixphpini.pl

3. Edit php.ini for internal cPanel PHP manually. Doing in this way only a last choice. Php.ini is likely to be reverted back after updating cPanel and you will need to redo it again.

3.1 Find your internal cPanel php.ini by call to https://{SERVER_IP}:2087/cgi/rvsitebuilder/rvdebug.php. It will display phpinfo page. Find the php.ini path.

3.2 SSH to the server as root.

3.3 Edit php.ini, insert these 2 lines under the extension_dir line.

zend_extension="/usr/local/IonCube/ioncube_loader_lin_5.2.so"
zend_extension_ts="/usr/local/IonCube/ioncube_loader_lin_5.2_ts.so

3.4 Run this command

/usr/local/cpanel/bin/install_php_inis

3.5 Restart cPanel services

/usr/local/cpanel/startup

3.6 Check your RVSitebuilder again.

4. Using this instruction only in case autofixphpini.pl doesn't help you.

4.1 Run this command manually.

perl /scripts/phpextensionmgr --prefix /usr/local/cpanel/3rdparty install IonCubeLoader

4.2 Create or update /scripts/postupcp to run above command every after cPanel upcp.

#!/usr/bin/perl
if (-f '/var/cpanel/rvglobalsoft/rvsitebuilder/panelmenus/cpanel/scripts/autofixphpini.pl') {
system('perl /var/cpanel/rvglobalsoft/rvsitebuilder/panelmenus/cpanel/scripts/autofixphpini.pl');
}
if (-f '/scripts/phpextensionmgr') {
system('perl /scripts/phpextensionmgr --prefix /usr/local/cpanel/3rdparty install IonCubeLoader');
}
1;

Make sure /scripts/postupcp permission is 700. You also need to test it by run /scripts/postupcp and check RVSiteBuilder again.