Hi @pxin, Sorry to hear you're having trouble! When using Affinity apps we always recommend moving your files from your external storage to your internal hard drive, as editing from an external drive can introduce multiple issues. It sounds as though when your Mac goes to sleep, access to the external USB is lost, then when returning from sleep Affinity is frozen as you had an image loaded from the external drive that has been disconnected and reconnected in the Sleep process.