Troubleshooting Tip: Internal 500 error when accessing some URLs and AV profile applied in Firewall policy

Description

This article describes how to resolve issues where the '500 Internal Error' screen appears.

Scope

FortiGate 7.4.x.

Solution

After an automatic update of the AV engine to version 7.00049, some users have reported failures that display the message 'Internal 500 error' in rules where AV profiles are enabled on firewall policies.

Workaround:

As a workaround, there are currently two alternatives:

• Remove the AV profile from the affected firewall policy, or:

• Enable the following configuration via the CLI:

config system global
    set av-failopen-session enable
end

Resolution:

The case is still under internal investigation for possible bugs in future releases.

Note: Enabling this option bypasses the scan unit whenever the throughput threshold is reached. It does not disable AV functionality.