If any of your apps don't work in MacOS Mojave, a small tweak in your settings might fix the problem

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!