Large holes in printed objects
Large holes in printed objects are almost exclusively caused by dirt on the FEP foil. Tiny pieces of debris on the bottom of the tank will block the light from reaching the resin correctly. Dirt particles have a tendency to grow during the print, which increases the size of the hole.
Solution: Make sure the FEP foil on the bottom of the tank is perfectly clean. Carefully remove any dirt / solidified bits. If the FEP foil is cloudy, use hot water and dishwashing soap to clean it and restore it to the original look.