I've had this every time I have updated the RouterOS on my 850Gx2, and it's really making me nervous about doing updates.
Is there anything I'm doing wrong, or missing?
Last time was when I got the advisory email about the botnet two weeks ago. I opened the web page for my router and clicked the 'check for updates' button. The router found the update, and got on with the process. Fifteen minutes later I still could not reconnect to the internet or to my router. I had to get the ladders out, and get up into the roof space to power cycle the router, hoping that would not brick it. Fortunately it didn't.
I've had to do that before, and also, twice, have had the router seem to come back online OK, but: It was dropping packets. The first time that happened I thought there was another cause (I was using a new service) but investigation tracked the start of the loss to when I recalled updating the firmware. Again, a power cycle was needed to stop the issue as I had already remotely rebooted it several times during troubleshooting.
The router performs flawlessly except immediately following an update.