Hi, Everyone, Brian here.

We have spent a week researching problems that some (many or most) Quicklook users, including Thumbnailer, are experiencing when they upgrade their Mac from Mojave to Catalina.

What we have found is this: New Catalina installs and new Macs do NOT have a problem. This is a problem with Apple’s Catalina Upgrade.

The problem affects ALL QUICKLOOK PLUGINS ON MAC. Other developers have reported it to Apple as well.

Apple knows about it.

Whether or not they’ll fix it is anyone’s guess. We think it unlikely, as Apple wants to go in another direction. Once they make that decision, they tend not to bother supporting the old stuff.

So what’s a user to do? If you have a Time Machine backup, you have the option of reverting to your your old MacOS. If you have that option, it may be desirable. That depends on you. What’s more important to you: The new features in Catalina or the Quicklook plugins like Thumbnailer?

What are we doing here at Embrilliance? Well there’s not much we can do for those who have the Catalina Upgrade and wish to keep it. The ball is in Apple’s court.

Next, we are looking into the new way Apple wants to do Quicklook. But as of today, there are no working examples that Apple has produced and their documentation is a few scant paragraphs that leave more questions than they answer. So it’s going to be trial and error, and may even take one more version of MacOS or XCode. We simply don’t know when this will work: It may work next week, it may work next year.

It Gets Worse.

Apple says they’re tightening up the Mac security in January. While they have made statements about what they’re planning, those plans change (such as with this month’s initial release of Catalina). All Embrilliance products are fully conformant to the app hardening which Apple has claimed as the January requirement. We have nothing more we can do today on that front.

Reading through comments from the developer community, we have learned that many app makers are quitting Apple. We are not. But you may find that some of your old favorite apps are going to disappear. We hope those folks will reconsider, but we understand how they feel.

On a personal note, Catalina reminds me of the launch of Windows Vista. These OS makers seem to need to suffer through a process of securing the OS that is so monumental it will dramatically affect the user experience. Eventually they will arrive at a livable compromise. What they do isn’t easy. So I’ll allow them some slack.

While my personal Mac development system now is Catalina, brought up from scratch, if I were a consumer, I’d wait and see on the OS upgrades, especially if you use Thumbnailer or any other Quicklook plugin.

As the situation changes, I’ll update this post accordingly.



Hi Everyone,

We now have updated Thumbnailer for Mac Catalina and Big Sur.

Please visit our website to download the update.

Downloads / Updates