audit – SCAP Compliance checker error for AWS EC2

I’m try to use Scap Compliance Checker 5.4 on a Windows laptop to scan remotely an EC2 Ubuntu 18.04, but it showed error. There’s plenty free space on the EC2, and I gave ubuntu full permission to /opt directory as well.

insufficient freespace ( MBs) in /opt. Miniumum required is 2048 MB.

Any suggestion ?