Adobe Photoshop wouldn't open after I upgraded to MacOS Mojave. But a simple trick fixed my problem — and it could fix your incompatible apps, too.
I have an old version of Adobe Photoshop I've kept on my laptop for many years now — it's CS5, for those of you keeping score.
When I upgraded my MacBook Pro to Mojave last month, I loved all of the changes, particularly the new Stacks feature. But I was bummed out when one of my most-used apps, Photoshop, would no longer open.
Every single time I clicked on Photoshop, it crashed, and could only produce an error report. There was nothing I could do to fix it — or so I thought.
After doing some sleuthing online, I learned that the kind folks at MacWorld UK had stumbled upon a trick that makes many seemingly-incompatible apps, like my old version of Adobe Photoshop, suddenly work on MacOS Mojave.
If you have an old version of Photoshop yourself, or have any other apps that don't seem to work in MacOS Mojave, try this trick first before giving up all hope:
First, open System Preferences.
Click on Security & Privacy.
Click on the far-right tab called "Privacy."
On the left sidebar, scroll down until you see the option that says "Accessibility." Click that.
You're going to have to click on the lock to make changes. Enter in your computer password.
Once you've entered your password, the list of apps on the right-hand panel will illuminate. Click on the app that isn't working for you — in my case, I'm trying to fix Adobe Photoshop CS5.
Clicking on the app allows it to control your computer again.
Now, click the lock again to save your changes. The apps in the right-side panel should dim again. That's it! Cross your fingers and try opening your app again.
This trick worked for me with Adobe Photoshop CS5 running on my 15-inch MacBook Pro, but your results may vary depending on the app that isn't working. Good luck!