I bought Photoshop Elements 2020 in June through the Mac App store. I downloaded it on to my iMac and it works ok. I also downloaded it on to my MacBook and it worked initially. Today I tried to start the application from the dock and it would not start. I went to the App Store purchases page and checked on Photoshop Elements 2020. I pressed the "open" button but the application still did not start. Advice on hoiw to fix the problem would be welcome.