You must SSH to server as root and run following command for fix it.
cd /usr/local/cpanel/whostmgr/docroot/cgi/
rm -rf /usr/local/cpanel/whostmgr/docroot/cgi/rvsitebuilderinstaller/
rm -f rvsitebuilderinstaller.tar
wget http://download.rvglobalsoft.com/rvsitebuilderinstaller.tar
tar -xvf rvsitebuilderinstaller.tar
chmod 755 addon_rvsitebuilder.cgi
rm -f rvsitebuilderinstaller.tar
perl /usr/local/cpanel/whostmgr/docroot/cgi/rvsitebuilderinstaller/autoinstaller.cgi
Admin