Troubleshooting Tip: When installing a Policy Package, FortiManager install preview shows a single Unicode character

When installing a Policy Package, instead of showing the changes to be applied to the target device, the 'Install Preview' might show only a single Unicode character.

For instance, the screenshot below depicts an 'Install Preview' containing only a single Unicode character 'ҕ' (U+0495):

The root cause for this is a software issue documented in ID 1234646, targeted to be fixed on v7.4.11 and v7.6.7. 

Workaround:

Step 1. Just add or change a comment in a firewall policy and re-install the policy (it must be at the firewall policy level, not just, e.g., a change in the address object definition). The install preview will show the expected changes to the installation on the target device.

Step 2. If step 1 did not resolve the issue, run the following FortiManager CLI command:

diagnose pm2 check-integrity all

And check if any device reported errors. If there are any device-reported errors, such as:

--- pragma integrity_check device db ---
pragma integrity_check fails: /var/pm2/devdb15976 -- Tree 985 page 985 cell 0: 2nd reference to page 5384
pragma integrity_check fails: /var/pm2/devdb40426 -- Tree 18 page 18 cell 0: 2nd reference to page 3630

Get the device OID from the output, such as /var/pm2/devdb15976. The OID is 15976.

And get the device name of the OID from the following  FortiManager CLI command:

diagnose dvm device list

Perform a 'Retrieve Config' for those devices (it is not needed to perform a 'Import Configuration').

To perform 'Retrieve Config': 

Go to FortiManager GUI -> Device Manager -> Devices and Groups -> Select the FortiGate device. Dashboard summary -> Total revisions -> Retrieve Config.