I'm having an issue with using undo in Photoshop. I recently updated to CC 2019 and Mojave at the same time. I am familiar with the changes Adobe made to the undo/step back shortcuts. When working in photoshop, undo will randomly not work (typically when I need it most). I can use "Toggle Last State" once, but have been caught in a predicament where I flattened the file, moved it and could only toggle the move, not the flattening, so the file had to be reverted to the last save. There is no rhyme or reason as far as I can tell, and if I try to replicate the issue, it will work fine, then randomly not work. When it happens, if I go up to edit, undo and redo will be greyed out, and toggle last state is active. If I toggle the last state, I still cannot undo or redo. I did discover that if I do get stuck, I can go into the history and cycle back through previous iterations. It's not a huge problem, it's just aggravating that it's not consistent, and I didn't know if there was some user error involved.
macOS Mojave 10.14
iMac (Retina 5K, 27-inch, 2017)
Photoshop CC 2019 20.0.0
We're really sorry for all the trouble. Have you tried restoring the Photoshop preferences back to defaults? If not, please do it. To know more about resetting Photoshop preferences, please refer: Preferences in Photoshop
If restoring preferences doesn't help then, turn on the "Legacy Compositing" in Photoshop preferences > Performance tab, restart Photoshop and check if that helps.
Have you customized your undo shortcuts?
From Edit > Keyboard Shortcuts, choose the "Photoshop default set" and then relaunch Photoshop.
Hey I recently updated as well.
I went into the keyboard settings and I switched the undo and the toggle last state commands.
The new settings were:
undo = cntrl + Z (this made it so that pressing ctrl +z multiple times would do multiple undos)
toggle last state = cntrl + alt + z (this made is so, pressing these buttons would only undo once)
Once i switched those commands ( so that Toggle last state= cntrl + Z, and Undo = cntrl + alt + z)
PS when back to normal functionality.
hope that makes sense!
I went into keyboard shortcuts, clicked on "use legacy undo shortcuts" and restarted photoshop. This seems to have solved the problem.
Oddly enough, something that has worked for me is switching focus to a non-Photoshop window and then returning to Photoshop. Magically, undo works again.