Alert log stopped working

Hello!

My instance of Dell OpenManage Enterprise has stopped collecting logs and sending alerts in some moment.

I see that the OME polls my devices without troubles and it shows their actual status, so I can see which devices are healthy and which ones have failed, but I don't see any new entries under /core/console/console.html#/core/diagnostic/log and probably because of that my Alert Policies don't work too.

The appliance shows no warnings or errors so I can't find the root cause of the problem. 

Can you advice what to do with it?

Thanks.