sudo /opt/nessus/sbin/nessuscli update /path/to/NessusUpdatePlugins-all-20.tar.gz
Ensure the file did not get corrupted during transfer. Check the MD5 checksum provided on the Tenable download page against your local file.
Choose and select your all-2.0.tar.gz file. Via Command Line (CLI) :
Please note: The string appears to contain a probable typo ( all20targz instead of all-2.0.tar.gz or similar). This report assumes the intent was to download a Nessus plugin update package.