Well if you’ve caught it early enough and the cracking hasn’t gone too deep then it’s not too much of a problem. It could have been caused by you applying the paint too thick or maybe you applied it in cold weather or possibly if you’ve painted a gloss over a very flexible paint system that was currently on. The way to solve this would be to remove any loose or flaking paint with a scraper or stiff bristle brush (not wire), sand any edges, prime the area and then repaint it. If the cracks have gone deeper then you’ll need to remove all the paint – right down – either by scraper, sanding or even using a heat gun – then primer and paint. Try using Sandtex Trade Flexigloss X-tra for added peace of mind.