"x" can't be opened because it is from an unidentified developer macOS Origin: Platform & cloud OSI layer 7 · Application Last updated 5 Nov 2026

macOS: “app” can’t be opened because it is from an unidentified developer

Gatekeeper refuses to open an app that isn't signed with a registered Developer ID.

Exact message you may see can't be opened because it is from an unidentified developercannot be opened because the developer cannot be verified“app” can’t be opened because it is from an unidentified developermacOS cannot verify the developer of this appunidentified developer macOS
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Seen on: macOS

Meaning

Right-click the app and choose Open (the dialog then offers Open), or allow it in Privacy & Security. On recent macOS the control-click trick is hidden for unsigned apps; use System Settings. For your own scripts and tools on the command line, clear quarantine with xattr.

Common causes

  • App signed ad-hoc or not at all
  • Downloaded from the web (quarantine attribute)
  • Old app never updated
  • Developer ID certificate expired/revoked
  • Packaged by a third party

⚡ Quick fix

  1. Right-click → Open
  2. Privacy & Security → Open Anyway
  3. xattr -d com.apple.quarantine /path/App.app only for trusted software

Detailed fix by platform

macOS

  1. spctl --assess -vv /Applications/MyApp.app shows why it's rejected

How to diagnose

  1. Signature — codesign -dv output?
  2. Quarantine — Attribute present?
  3. Trust — Software trusted?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: Platform & cloud. Errors that are often confused with or caused by this one (click to open):

ActiveModel::ForbiddenAttributesError (strong parameters) — Rails: ActiveModel::ForbiddenAttributesError (Ruby / Rails)ActiveModel::Forbidde…Apple could not verify "x" is free of malware — macOS: “app” cannot be opened because Apple cannot check it for malicious software / Apple could not verify “app” is free of malware that may harm your Mac (macOS)Apple could not verif…codesign: resource fork, Finder information, or similar detritus not allowed — macOS: Error: resource fork, Finder information, or similar detritus not allowed (macOS)codesign: resource fo…Homebrew Cask: It seems there is already an App at — Homebrew: Error: It seems there is already an App at '/Applications/Chrome.app' (macOS)Homebrew Cask: It see…is damaged and can’t be opened — macOS: “App” is damaged and can’t be opened. You should move it to the Trash. (macOS)is damaged and can’t …System software from "x" was blocked from loading — macOS: System Extension Blocked — A program tried to load new system extension(s) / System software was blocked from loading (macOS)System software from …The specified item could not be found in the keychain (-25300) — macOS: security: SecKeychainSearchCopyNext: The specified item could not be found in the keychain. (errSecItemNotFound -25300) (macOS)The specified item co…zsh: bad CPU type in executable — macOS (Apple Silicon): zsh: bad CPU type in executable: ./tool (macOS)zsh: bad CPU type in …"x" can't…

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