Comment 1 for bug 1712817

Do you still have your terminal log from before the bits you showed in the bug report?

Even if you have the service stopped, upgrading the packages would have restarted it, and the freeradius-ldap postinst would encounter the service running. Unless that earlier restart failed.

In freeradius.postinst, notice the "|| true" suffix ($action is either start or restart):
          invoke-rc.d freeradius $action || true

Then comes freeradius-ldap:
          invoke-rc.d freeradius force-reload

There the action will indeed fail if freeradius isn't runing.

Here are both scenarios. First, the failure:
oot@xenial-freeradius-1712817:~# systemctl stop freeradius.service
root@xenial-freeradius-1712817:~# apt install --reinstall freeradius-ldap
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/24.2 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 28097 files and directories currently installed.)
Preparing to unpack .../freeradius-ldap_2.2.8+dfsg-0.1ubuntu0.1_amd64.deb ...
Unpacking freeradius-ldap (2.2.8+dfsg-0.1ubuntu0.1) over (2.2.8+dfsg-0.1ubuntu0.1) ...
Setting up freeradius-ldap (2.2.8+dfsg-0.1ubuntu0.1) ...
freeradius.service is not active, cannot reload.
invoke-rc.d: initscript freeradius, action "force-reload" failed.
dpkg: error processing package freeradius-ldap (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 freeradius-ldap
E: Sub-process /usr/bin/dpkg returned an error code (1)

Now a proper upgrade, which includes freeradius itself:
root@xenial-freeradius-1712817:~# systemctl stop freeradius.service
root@xenial-freeradius-1712817:~# apt install --reinstall freeradius freeradius-ldap
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 2 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/550 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 28097 files and directories currently installed.)
Preparing to unpack .../freeradius_2.2.8+dfsg-0.1ubuntu0.1_amd64.deb ...
Unpacking freeradius (2.2.8+dfsg-0.1ubuntu0.1) over (2.2.8+dfsg-0.1ubuntu0.1) ...
Preparing to unpack .../freeradius-ldap_2.2.8+dfsg-0.1ubuntu0.1_amd64.deb ...
Unpacking freeradius-ldap (2.2.8+dfsg-0.1ubuntu0.1) over (2.2.8+dfsg-0.1ubuntu0.1) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu19) ...
Setting up freeradius (2.2.8+dfsg-0.1ubuntu0.1) ...
Setting up freeradius-ldap (2.2.8+dfsg-0.1ubuntu0.1) ...
root@xenial-freeradius-1712817:~#

I suspect the restart done by the freeradius postinst in your case failed and was masked by the "|| true" bit, or that the service started but died right afterwards.

Could you please check that your terminal had nothing else related to a freeradius restart before what you pasted in your bug report?

And also please attach a copy of /var/log/freeradius/radius.log as it may have information on the running state of the service, and any errors that it might have encountered.

Thanks!