How do i fix my crackled paint?

I have painted part of my hallway in the Dulux light and space paint but didn't prepare properly as i was painting over a shiny (possibly satin) paint and now the paint has crackled. The first coat was fine but its happened as i've put the 2nd coat one.





So how do i rectify that problem and also what do i need to do to prepare the bits i haven't yet done. The ceilings are 12 ft up over the stairs so not sure how i could sand all the way to the top - have been using paintbrush strapped to a pole!!!How do i fix my crackled paint?
By the sound of it you have put the second coat on to soon. If the first coat was fine (dry to the touch) it might not have cured properly.When applying a second coat over paint that has not dried properly the paint can crocodile ( have a wrinkled appearance). You need to let that harden then sand out. As for the unpainted parts of the wall give a good sanding to remove gloss and then paint.