Mango - configuration gone


I just experienced weird issue after couple of months of using Mango.
I unplugged it from power last night, powered it back again today and it was reset to factory defaults - all configuration gone (except saved wifi hotspot it uses to connect to the Internet). So it connected to the Internet, but VPN configuratiin, Internet kill switch, ssid config, admin web password…all reseted to default.
Please advise if this is a known issue for you and where can I check the logs to see what caused it?
I did not press reset button nor did any config changes.
I have the latest available software on it 3.211

Did you install some software packages and the flash is full?

No issues with flash size. Any other ideas?
I installed Luci and checked the logs buy not much in there.

Very strange.

Maybe you can just reset the router and start over.

The first time met such case.