When I use Sharpen on an image and then press "Save" the processed image just disappears. The image remains untouched in my iPhoto file.
Maybe there is a button in Topaz where need to accept the process to lock in the change before you save it.
I know nothing about Apple, but I'll offer a link I found:
https://community.topazlabs.com/t/cannot-save-image-in-sharpen-ai-v2-0-5/14325/3Scroll below the Windows reply to the conversations about Mac.
Also, you say iPhoto in your text, but Apple Photos in your title. Apparently, those are two different things, with iPhoto being an "obsolete" app. If no one else sees this thread, and you don't have a "save as" or "export" option when you finish your edit, perhaps open a trouble ticket with Topaz?
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