WNDR3800 is s stable old device, so that looks a bit strange.
Just reboot the device, and hope that this time things keep running.
Note that the logged faults have happened right after the boot and then at every 6 seconds. So you should see rather quickly if the same happens again.
You might also try a newer 17.01 build. E.g. my community build for WNDR3700/3800 has a month newer version. Build for WNDR3700v1/v2 / WNDR3800