Is it safe to prepare a crock pot recipe the night before?
Assuming it's a proper removable (some old ones weren't) inner crock pot you could (as in your other answer).

BUT

That pot will take a long time to warm up when you put it in and turn it on.  I would suggest assembling all the ingredients in another container (which may also fit better in the fridge) and turning them out in to the (ideally preheated) crock pot in the morning.  Otherwise you will probably need to add some time even on top of the extra time for starting all ingredients at fridge temperature.

This is roughly what the manual for our previous slow cooker recommended.  Our new one is a non-stick steel inner pot (for easy browning) and will warm up much faster - there's no  recommendation to preheat this model.