The stuff pasta shapes are outlines in the Stuffed section, but there is general advice to be given that will apply for any stuffed pasta.
Air Pockets Are Your Enemy
When closing and sealing stuffed pasta, air can get trapped inside. During cooking, the trapped air will expand and cause the stuffed ravioli to pop. You then have a pot of boiling water, floating loose filling, and deflated and empty pasta balloons. There will always be a tiny amount of air trapped, but when starting out with pasta making, try to avoid large air bubbles.
Double Check The Seal and Thin It
A weak seal can also cause a stuffed pasta to fall apart. Take the time to go over a seal a second time to ensure it is closed and to also make the seal a little thinner. Because the seal is two pieces of dough, it is twice as thick and will take slightly longer to cook. This will make for a better seal and a more evenly cooked finish product.
Don’t Overstuff
Overstuffed pasta can also cause a stuffed pasta to fail. Make sure that there is a border of dough between the edge of the pasta and the filling so that a sufficient seal can be made. I usually leave about 1/4 inch.