I can't open PDF files with Preview

Question

Level 1

18 points

After I did the latest update (to Sequoia 15.7.3) suddenly I am getting this error message when I try to open apps:

"(Files) can't be opened because the identity of the developer cannot be confirmed."

I was able to download an app that wasn't working from the app store.

However, I have discovered that I can't open any PDF files with preview.

Help!

iMac (M1, 2021)

Posted on Dec 15, 2025 3:40 PM

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Answer 1

Level 1

18 points

Here is what I have tried:

Choose Finder > Go > Go to Folder..., paste the following line, and press the Return key:

Starting up from safe boot. (It still happens)
Reinstalling the operating system. (It still happens).
Removing the "com.apple.Preview.plist" file from the "~/Library/Containers/com.apple.Preview/Data/Library/Preferences/" file. (It still happens.)

Why are PDF files getting labelled as "foreign software"?!?

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