If you're facing problem on RVsitebuilder 6 Setup in WHM. You can check and fix it by following.
Check error log:
tail -f /usr/local/cpanel/logs/error_log
PHP Fatal error: Uncaught Error: Call to undefined function dl() in /usr/local/cpanel/whostmgr/docroot/cgi/rvsitebuilderinstaller/ioncLoader.php:83
Stack trace:
#0 /usr/local/cpanel/whostmgr/docroot/cgi/rvsitebuilderinstaller/index.php(19): require_once()
Solution:
WHM > Tweak setting > cPanel PHP loader on save
WHM > Plugin > Rvsitebuilder /manager > Setup Rvsitebuilder again
Admin