Depending on your Mac OS security settings, your Topaz Labs app installation may be interrupted by a window that looks like this:
To open our apps regardless of your security settings, follow these steps:
In the Finder on your Mac, locate the app you want to open.
Don’t use Launchpad to do this. Launchpad doesn’t allow you to access the shortcut menu.
Control-click the app icon, then choose Open from the shortcut menu.
The app is saved as an exception to your security settings, and you can open it in the future by double-clicking it just as you can any registered app.
Apple's support website has an article with more information on its security settings with additional troubleshooting steps if you need them. You can access it by following this link.