Copy all layers and merge hotkey not working CC 2019

Sahil, I'm finding this a problem as well; "Cmd + option + shift + E" no longer works. I can't find anything called "Stamp Visible." The information for the above article seems outdated (the video used CS6). Any ideas?

Be sure you have a visible layer selected when you invoke it

It's called Stamp Visible.  For some odd reason, it has never appeared in the keyboard shortcut list, it's always just existed. It's working fine for me in the latest update of Photoshop, so not sure what's up other than you possible reassigned that keyboard shortcut to something else. If you did, you might want to find it in your list of shortcuts and delete it and see if that restores the original version.

Also, you can try resetting the preferences as Sahil said above.

You could also go into the Keyboard shortcuts list and try switching it back to the Photoshop Defaults and see if it is working there with no shortcuts being modified.

If it's not working at that point, definitely try the preferences reset. And if that doesn't work, you may need to just uninstall photoshop and then reinstall it.

Hi Jessica,

Sorry to hear that, could you please let us know the operating system you're working on?
Could you please try resetting the preferences of Photoshop and let us know if it helps with the issue?

Preferences Reset Article Photoshop - https://helpx.adobe.com/photoshop/using/preferences.html

Regards,
Sahil