RB493AH crashing once/day after RouterOS + Firmware upgrade :(

Two days ago I upgraded our FW from Firmware 2.23 to 3.24 and the packages to 6.34.3 (do not recall what version I was at before).

Yesterday, the FW crashed (or at least no longer communicated on the network). A reboot resolved.

I enabled the watchdog and configured it w/ automatic supout (both saving the file and emailing) as well as enabled disk logging for critical errors. No supout or log entries were created.

It just crashed again today.

I’ve hooked up a serial cable so I can see if it is responsive next time – but obviously I don’t have a lot of time to investigate in the middle of an outage.

I think these may be the first two MT crashes I’ve witnesses across a lot of years and variety of devices – so it seems pretty likely that one of the recent upgrades is to blame.

Q1: is this a known issue?

Q2: any thoughts on whether this is related to the firmware or the routerOS?

Q3: if the firmware is likely the culprit, is there a way to “downgrade” short of a full factory reset (assuming that does downgrade the firmware)

Q4: if the routeros is the likely culprit, do I need to use the “downgrade” option in software/packages or can I restore from the backup I took before the ugprade?

Be careful with backups, they are only intended for a given device, and a given ROS version, the proper way to move configurations between routers, or when doing upgrades is by using exports. See http://wiki.mikrotik.com/wiki/Manual:Configuration_Management

Given the “huge” upgrade, I’d do an export, reset to no defaults then reload the configuration using import verbose=yes to check for any errors.

If problem persists, next step to try is a netinstall.