Heads Up :
The post you are writing will appear in a public forum. Please ensure all content is appropriate for public consumption. Review the employee guidelines for the community here.
That error just means the Cisco AnyConnect CLI binary (vpn) isn't actually installed at that path — /opt/cisco/anyconnect/bin/ is empty or the client was never installed. On a headless server you usually don't want the full Cisco Secure Client anyway...
