Technical Tip: Best practice procedure to upgrade FortiClient EMS v7.4.3 to v7.4.7 or a higher version

Description

This article describes the best practices to upgrade FortiClient EMS v7.4.3 to v7.4.5 or a higher version.

Scope

FortiClient EMS v7.4.3.

Solution

When attempting to upgrade FortiClient EMS v7.4.3 to v7.4.5 or a higher version, the upgrade may fail with the following messages:

cp: cannot stat '/opt/forticlientems/tmp/signatures/07004000/wordscategory.enc': No such file or directory.
dpkg: error processing package forticlientems (--configure):
E: Sub-process /usr/bin/dpkg returned an error code (1)

cp: not writing through dangling symlink '/tmp/forticlientems/upgrade/signatures/07004000/wordscategory.enc'
dpkg: error processing package forticlientems (--configure):
 installed forticlientems package post-installation script subprocess returned error exit status 1
Processing triggers for libc-bin (2.39-0ubuntu8.8) ...
Processing triggers for man-db (2.12.0-4build2) ...
Processing triggers for postgresql-common (293.pgdg24.04+1) ...
Building PostgreSQL dictionaries from installed myspell/hunspell packages...
Removing obsolete dictionary files:
Errors were encountered while processing:
 forticlientems
needrestart is being skipped since dpkg has failed
E: Sub-process /usr/bin/dpkg returned an error code (1)
This was an upgrade so a few dependencies may need to be upgraded...
Upgrading pgagent...

When faced with this issue, make sure to take a copy a of the upgrade failure logs on the local machine.

An example of the two required log file names is provided below:

/var/log/forticlientems/forticlientems_2026-MM-DD_upgrade_db.log
/home/ems/exchange/forticlientems-install-20260MMDDxxxx.log

Next, rollback the FortiClient EMS server to a working VM snapshot prior to the upgrade attempt.

Solution:

1. Raise a FortiCare ticket via the Support portal.

2. Attach the two upgrade failure log files on the ticket.

3. After issue validation, Fortinet TAC may provide a hotfix file: FortiClient EMS v7.4.3 hotfix package.

4. Take a VM snapshot before applying the hotfix.

5. Apply the hotfix on FortiClient EMS v7.4.3.

6. Take another VM snapshot before FortiClient EMS upgrade attempt.

7. Perform a FortiClient EMS upgrade to v7.4.7.

8. The upgrade should be successful.

Note: Do not upgrade FortiClient EMS v7.4.3 directly to FortiClient EMS v7.4.8, as it is not supported.

The best upgrade path to upgrade to v7.4.8 is:

1. Start from FortiClient EMS v7.4.3.

2. Apply the hotfix above.

3. Upgrade to v7.4.7.

4. Apply another FortiClient EMS v7.4.7 hotfix package (which will be provided by Fortinet Support if necessary).

5. Upgrade to v7.4.8.