When layers are not separated, cured resin will later stick on the vat floor. It could be hard to clean up scattered cured resins such as layers for supports without pouring out the resin. Here is a solution. You can lift the platform and print just layer one (attachment layer) for a minute. A thin cured layer will form on the vat floor. Remove this layer with a plastic blade from the vat floor and you will remove all other previously cured resin at the same time.