VAS Warning: "Unrecognized setting: [libdefaults] use_fast" (4383313)

Safeguard Authentication Services (VAS) may log the following warning:
WARNING: Unrecognized setting: [libdefaults] use_fast

This is observed when the following setting exists in /etc/opt/quest/vas/vas.conf:
[libdefaults]
use_fast = true

The use_fast parameter is related to Kerberos FAST (Flexible Authentication Secure Tunneling / armoring).
FAST support is only available in the following VAS versions:

6.1
6.2
7.0

On other/earlier versions, use_fast is not recognized, resulting in the warning message during configuration parsing.

No action is required.

This is an informational warning only.
VAS ignores the unrecognized setting and continues to operate normally.
Authentication and VAS functionality are not affected.

Fix: 
Upgrade to a supported version (6.1, 6.2, or 7.0+) that supports FAST.

Workaround: 
Move the status script from a supported version to the older version.

This version will recognize the setting and not report on it when running "vastool status" 
/opt/quest/libexec/vas/scripts/vas_status.sh