macOSMojava

Try trashing the prefs which is often necessary after updating Mac OS. These instructions are for PSE 2019 but you can find the corresponding PSE12 files/folders

Quit Elements

Launch Finder and go to your Username >>Library >> Preferences

Send the following files/folders to the trash:

Adobe Photoshop Elements 17 Paths

Adobe Photoshop Elements 17 Settings

com.adobe.Elements Organizer.17.plist

com.adobe.PhotoshopElements.plist

The library is hidden in recent versions of Mac OS. To get to your user library quickly, from the top menu in Finder, click “Go” whilst holding down the Option (Alt) key and your user Library will appear for you to choose.

One other thing to try:

Click System Preferences in the dock and open Security & Privacy

Choose the Privacy tab and the choose Accessibility

Click the lock to unlock (you may be prompted for your Apple system login password)

Then click the plus button to add the Editor and/or Organizer app. If already listed ensure it has a checkmark. See image below.

Navigate to:

To add the Editor:

Macintosh HD >> Applications >> Adobe Photoshop Elements 2019 >> Support Files

Choose (highlight) Adobe Photoshop Elements Editor.app and click open

To add the Organizer:

Macintosh HD >> Applications

Choose (highlight) Adobe Elements 2019 Organizer.app and click open

Re-lock and try launching Elements again. Even if not added to the control list, this often makes a difference after closing Security & Privacy.

Let us know if it works.

Obviously you need to find the PSE12 apps as the above instructions relate to the latest version.