Cannot Open Photoshop 26.9 on Mac Studio running Mac OS 15.6 Sequoia with M2 Ultra chip

[panther creek]

The subject says it all.

[LAMY2017]

When did this problem start happening? I'm sure your system meets the system requirements.

Have you recently upgraded to v26.9? What are the symptoms? Error messages?

[panther creek]

I updated to 26.9 about a week ago. I updated to Mac OS 15.6 two days ago. Nothing happens except the splash screen shows up for 5 seconds and disappears. The app doesn't open. No error message. 

[LAMY2017]

My crystal ball says "maybe it's a permissions issue." 

I didn't have a problem with Ps26.9 and MacOS 15.6 but maybe because I installed the OS upgrade before the Ps update.

Can't hurt to uninstall v26.9 and reinstall.

Out of curiosity, check activity monitor for one instance, maybe multiple instances, of the Adobe Photoshop 2025 process.

Enter 'Adobe Photoshop 2025' in the search window at the upper-right of Activity Monitor to screen out all other apps' processes.

You'll see three other associated processes (Web Content, Networking, Graphics & Media).

[panther creek]

Thanks. I'll look at the activity monitor. BTW, I've performed all of Adobe's suggestions to try to fix this type of problem to no avail, including multiple uninstall/reinstall sequences of both Photoshop and Creative Cloud. 

[LAMY2017]

I've had a similar issue a few times in the past, where the Ps icon in the Dock didn't open Ps when clicked.

[apparently, the dock icon doesn't always get linked to the new version]

Test: open Ps from the Applications folder. If it opens, delete the current icon in Dock.

[panther creek]

Thanks. I tried that also. 

[LAMY2017]

My last-ditch thought: In Finder, right-click on a Raw or JPEG file; is Adobe Photoshop 2025.app a/the choice? If yes, when selected, will Ps open?

[panther creek]

Nope, PS doesn't open.  

[Jeff Arola]

panther creek,

Have you tried resetting the Photoshop preferences?

https://helpx.adobe.com/photoshop/using/preferences.html

Also try holding the Shift key while launching Photoshop to skip loading any third party or optional plugins, which may cause issues as well.

[panther creek]

Thanks.  I already tried resetting the preferences.  However, when I held down the shift key to skip loading 3rd party plugins, PHOTOSHOP OPENED! However, I don't know where to go from here to find out which plugin or plugins is the problem.

[panther creek]

When I tried opening PS without holding the shift key, it would not open.  The splash screen was only open long enough to display "InnerLoop Plugins Loaded."  I have no idea what they are, but they may be part of the problem.

[Jeff Arola]

Do you have any third party plugins like OnOne?

You can look in for any installed third party plugins:

Applications/Adobe Photoshop 2025/Plug-ins

and

Macintosh HD/Library/Application Support/Adobe/Plug-Ins/CC

Here's an Adobe KB on the subject:

https://helpx.adobe.com/photoshop/kb/plug-ins-photoshop-troubleshooting.html

[panther creek]

Yes.  I've moved all plugins to a desktop folder and PS still won't start.  I also tried moving them one at a time.

[M-H]

Try also C:\Users\[your user name]\AppData\Roaming\Adobe\UXP\Plugins\External

[panther creek · Accepted solution]

I'm on a Mac so that won't work. 
Anyway I found out that the problems were with some OnOne plugins. When I removed them everything was fine. 
Now I'll let OnOne know some of their plugins don't work on a Mac with OS15.6

[LAMY2017]

I know it was laborious and frustrating, but kudos on your troubleshooting.

[panther creek]

Thank you.