I just purchased the 2021 PSE and did the disc install on my 6 month old Mac mini with Big Slur. At completion of install, there was an update message, which I performed. The problem I experienced is when there are two files open, showing side by side. I attempted to drag a layer from one file to the other, and crash, it quit. I have reopened it and repeated the process again, crash. Is this a known bug?