What’s making previews unreliable?

Shine a spotlight on the solutions to your most irritating Mac problems

When I preview a single Adobe Photoshop PSD image, Quick Look works fine, but they’re shown as generic thumbnails when in multiple views. Can I fix this?

Quick Look, responsible for Finder thumbnails and previews of documents, has undergone major change in macOS 15 (Sequoia). While it still supports a broad range of file types — for instance, generating thumbnails and previews of common formats, including many image types — those requiring third–party generators can’t use the traditional generators from the past. Previewing multiple documents works fine for the most common formats and types, such as JPEG and HEIC. If it doesn’t work forPhotoshop PSD files, there’s nothing you can do to fix it yourself, but you should report it as a bug.

To work out what’s at fault here, you first need to discover the Uniform Type Identifier (UTI) for the file type in question; for PSD images, that’s com. adobe.photoshop–image. You can then look that up in the list of generators and app extensions using the command: qlmanage –m plugins or from the Quick Look button in the free utility Mints from bit.ly/mac418mints.