Pi b crashing

[sunnyvk]

Please refer to this discussion which looks similar to your problem…

Not booting after December update

A small update to this issue - we have built a new Pi kernel (4.3.3-2) which includes the missing mmc-overlay.dtb file, so anybody updating to the December release from today onwards who experiences this problem, it is sufficient to just add dtoverlay=mmc to /boot/config.txt to revert to the mmc driver - no downloading and copying of the dtb file is necessary now. (Also make sure there is no line that says dtoverlay=sdhost in config.txt) If you are using a Noobs install, hold shift when booting…