Comment 0 for bug 1855415

I have attached the machin using "sudo ua attach ###code".
then the following happens:
#command & output
$ sudo ua status
SERVICE ENTITLED STATUS DESCRIPTION
cc-eal yes n/a Common Criteria EAL2 Provisioning Packages
cis-audit no — Center for Internet Security Audit Tools
esm-infra yes disabled UA Infra: Extended Security Maintenance
fips yes n/a NIST-certified FIPS modules
fips-updates yes n/a Uncertified security updates to FIPS modules
livepatch yes n/a Canonical Livepatch service

Enable services with: ua enable <service>

     Account: <email address hidden>
Subscription: <email address hidden>

When I am trying to enable esm-infra, I am getting;
~$ sudo ua enable esm-infra
One moment, checking your subscription first
Updating package lists
Updating package lists
APT update failed.

I have tried
$ sudo rm -vf /var/lib/apt/lists/* -vf
$ sudo apt-get clean
$ sudo apt-get update
$ sudo ua enable esm-infra

But no luck. Please help.

$ lsb_release -rd
Description: Ubuntu 14.04.6 LTS
Release: 14.04

$ apt-cache policy ubuntu-advantage-tools
ubuntu-advantage-tools:
  Installed: 19.6~ubuntu14.04.3
  Candidate: 19.6~ubuntu14.04.3
  Version table:
 *** 19.6~ubuntu14.04.3 0
        500 http://archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        100 /var/lib/dpkg/status