I have Element 13 in lightroom as an external editor but pictures do not load when i try and use it! Imac, lightroom 5.7.1
Some users make the mistake of choosing the Adobe Photoshop Alias rather than the app.
When setting up LR External Editing in prefs navigate to:
Applications/Adobe Photoshop Elements 13/Support Files/Photoshop Elements 13 Editor
While you're setting Photoshop Elements up as an External Editor, make sure you choose the "Photoshop Elements Editor" not the alias for Photoshop Elements (which launches the welcome screen) and do not load the image:
Retrieving data ...