The following error happens when creating website in RVsitebuilder 7.
Error encountered while running 'tar' command. gzip: stdin has more than one entry--rest ignored /bin/tar: Child returned status 2 /bin/tar: Error is not recoverable: exiting now
RVsitebuilder 7 plugin on this server is an outdated version (might be 7.0 that doesn't provide auto-update on RVsitebuilder plugin).
Contact your host provider to run update RVsitebuilder 7 on this server with the following command.
cd /usr/src; rm -fv rvsitebuilder7install.sh; wget http://download.rvglobalsoft.com/rvsitebuilder7install.sh; chmod +x rvsitebuilder7install.sh; ./rvsitebuilder7install.sh
After that, try access to control panel to create website in RVSitebuilder 7. It should be working fine.