It looks like the mix was a bit dry and a heavy knock down, if there is not enough moisture in the mud or the wall was not prepped well this happens. It is hard to tell is this a patch? If doing an entire area after taping and sanding I usually wipe the wall with a damp towel to remove dust, when I have large jobs done my mud slinger says why wast the time just add water (he is way faster than I am and his work looks good) so I would guess your pre mix is a bit dry you might be able to flake it off with a putty knife but it will need to be removed. Pre mix separates when sitting on the shelf so it needs to be mixed in most cases and for texture I usually add a fair amount of water, for heavy knock down about a cup to a box, for spray knockdown 2 or more cups let it sit then knock down. So to get back on track remove the material that is cracking add some water to your mud and give it another try. Texture is a bit of an art and the amount of water varies with the conditions both humidity and temperature.