It would also help to now if its a sv2, MMP or MM esc. I had the motor plug pull out on my SV2 from normal use.
And what in the world is a cracking sound? Like the sound of a tooth pick being snapped or wood splintering?
+1 on checking the solder joints, you could have a battery plug that is weakened from vibration.
But ultimately, get a reliable esc.
lulz, castle stuff has been pretty good to me. If you do a search you will find failure with any ESC, so blanket statements like this are pretty silly.