Photoshop uninstalled itself on my computer.

Hello and thank you for a very plausible explanation. I went to my Time Machine backups and reset the computer to 48 hours prior to the when the problem occurred, reset the corrupted disk error by changing to the default settings and updated the OS.

There is no way Photoshop can uninstall itself. An uninstall needs to be user iniated through several steps.

The only theoretical possibility I can think of is this: automatic updates is enabled in the CC app, but the hardware doesn’t meet the system requirements for the update.That will abort the update, but unfortunately, the installer is set to remove old versions before installing the new. So it’s conceivable that the hardware check somehow skipped a step and removed the old while not installing a new.

It’s much more likely that a problem occurred that prevented the app from opening. And the most likely issue would be a relatively trivial thing like corrupt preferences, which is easily reset.

Either way, this is just speculation until we see screenshots of the actual error messages you got. 

Exact message said “photoshop cannot open”  I rebooted yesterday afternoon because my system was slow. Photoshop worked fine prior to that. I have now reinstalled Photoshop but all my Presets, Actions and Brushes are gone. 

​@pamela winter 

 … I went to my Creative Cloud and it said Photoshop was not installed. ...

I’ve never heard the a allpication is deinstalled by itself. What has been done/changed on system before the issue occur?

… but I kept getting a message that it cannot open. ...

What’s the exact error message?