Logging FortiOS 5.4.1 to FAZ 5.2.x in syslog. (IM)possible?

[virtualj]

Hi,

I have a Fortigate 50E and it only run 5.4.1. All my other firewalls are 5.2.x or 5.0.x. Also my fortianalyzer is 5.2.9 and it is not compatible with FortiOS 5.4.x.

So I think to configure Fortigate to send logs in syslog mode to the FAZ for archiving (not for reporting), but it doen't work.

What can be the problem? I'm not able to manually add a syslog device with the fotigate SN (error received: SN doesn't match database) and I don't see SN under unregistered devices.

For the moment I can't update my FAZ.

Any ideas?

Thank you.