I have the exact same programs running in the background as before today, and before there has been no issue at all. My history settings is set to 100 so that is definitely not the problem. I have found out however that whenever I select the 'alt' button on my graphics tablet along with ctrl+z it works fine, but it's just so finicky that I can't get around it. I tested my alt key in multiple programs and it works perfectly.
I tried changing the shortcut to something else and then changing it back, but whenever I use my three keys at the same time the box stays completely blank. I tried reinstalling PS and the problem is the same. I use Photoshop almost every day for college work and suddenly today my step backwards shortcut stopped working and I can't for the life of me get it to work.
