Hi,

This happens when the installation was interrupted for the 1st time or for some reason the Softaculous folder already exists e.g for cPanel :
/usr/local/cpanel/whostmgr/docroot/cgi/softaculous/

This folder exists but it has some files missing.

The Softaculous installer checks if this folder already exists we do not unzip the package again hence causing the above error due to missing files.

You can delete the Softaculous directory or make a backup of Softaculous directory (if you have any data in it) and then try to install again and it should work.

Do let us know if you still face the issue.