"App is damaged and can't be opened" — Gatekeeper on macOS

macOS won't let me open LM Studio, Jan or a llama.cpp binary

作者 Jakub Rusinowski

错误信息

"LM Studio" is damaged and can't be opened. You should move it to the Bin.

"llama-cli" cannot be opened because the developer cannot be verified.

Apple could not verify "Jan" is free of malware that may harm your Mac or compromise your privacy.

1. 1

   Verify the download before you bypass anything

   Do this first, every time. Download only from the project's official domain or its GitHub releases page. Compare the SHA-256 against the published checksum where the project publishes one. Check the signature with codesign — it tells you whether the binary is signed at all and by whom, and spctl tells you what Gatekeeper's own assessment is. An unsigned build from the project's own release page is a normal state of affairs; an unsigned build from a link someone posted is not.

   注意：Everything below removes or bypasses a macOS safety check. That is reasonable for a binary you have verified and reckless for one you have not. If you cannot establish where the file came from, the correct action is to delete it.

   zsh复制

   # zsh
   shasum -a 256 ~/Downloads/LMStudio.dmg
   
   # Is it signed, and by whom?
   codesign -dv --verbose=4 /Applications/LM\ Studio.app 2>&1 | head -12
   
   # What does Gatekeeper itself say?
   spctl --assess --type execute --verbose /Applications/LM\ Studio.app

   生效了吗？The hash matches the published checksum, and codesign names a signer you recognise — or the project is openly unsigned and you fetched it from its own release page.
2. 2

   Right-click → Open — the narrowest fix that works

   For an app that is merely unverified rather than "damaged", right-click (or Control-click) the app in Finder and choose Open, then confirm in the dialog. This creates a one-off exception for that specific app and changes no system setting. Double-clicking will not offer the exception; the context menu is what does it. That difference is the whole trick and it is not discoverable.

   生效了吗？The app launches, and subsequent launches work normally by double-click.

   zsh复制

   spctl --assess --type execute --verbose /Applications/LM\ Studio.app

3. 3

   Use "Open Anyway" in System Settings

   If the right-click route does not offer an Open option, try to launch it once so macOS records the block, then go to System Settings → Privacy & Security, scroll to the Security section, and click Open Anyway next to the message naming your app. The button appears only after a blocked attempt, which is why people who go looking for it first do not find it.

   生效了吗？The app opens and the entry disappears from Privacy & Security, having been resolved.
4. 4

   Remove the quarantine attribute — only for a verified binary

   When the first two do not work — commonly for CLI binaries and .dylib files rather than .app bundles — remove the attribute directly. Scope it as tightly as you can: name the single file where you can, and the specific app or package directory otherwise. Check first with xattr -l that quarantine is actually the attribute present, so you know this is the right tool.

   注意：xattr -dr com.apple.quarantine strips the OS safety check from everything under the path you give it. Never run it against your Downloads folder, your home directory, or /Applications as a whole — only against the one app or file you have verified.

   zsh复制

   # zsh — what attributes does the file actually carry?
   xattr -l /Applications/Jan.app
   
   # Remove quarantine from ONE verified app
   xattr -dr com.apple.quarantine /Applications/Jan.app
   
   # A single CLI binary from a release archive
   xattr -d com.apple.quarantine ./llama-cli

   生效了吗？xattr -l no longer lists com.apple.quarantine for that path, and the binary runs.

   zsh复制

   xattr -l /Applications/Jan.app; ./llama-cli --version

5. 5

   Prefer Homebrew casks, which sidestep most of this最常见的修复方法

   Installing through brew install --cask avoids the majority of these prompts, because Homebrew fetches the file itself rather than a browser and handles quarantine as part of the install. It also gives you a maintained upgrade path, which matters for fast-moving projects where you would otherwise re-download and re-bypass every few weeks. This is the better default for anything Homebrew packages.

   zsh复制

   # zsh
   brew install --cask lm-studio
   brew install ollama
   
   # Keep them current without repeating the whole dance
   brew upgrade --cask

   生效了吗？The app launches directly from /Applications with no Gatekeeper prompt.

   zsh复制

   brew list --cask | grep -i studio

   检查哪些模型适配你的硬件pick a model sized for your Mac once the app opens打开显存检查器 →
6. 6

   Handle the Python and dylib case

   A Python package can install cleanly and then fail at import because a bundled .dylib inside the wheel is quarantined — the error mentions the library rather than anything about security, so the connection is not obvious. Find the quarantined files under the package directory and clear those specific ones. If a package repeatedly needs this, prefer a wheel built for your architecture from the project's own index, which usually does not.

   zsh复制

   # zsh — find quarantined libraries inside a virtualenv
   find .venv -name "*.dylib" -exec xattr -l {} ; -print 2>/dev/null | grep -B1 quarantine
   
   # Clear them for that package only
   xattr -dr com.apple.quarantine .venv/lib/python3.12/site-packages/<package>

   生效了吗？The import succeeds and xattr -l on the library reports no quarantine attribute.

   zsh复制

   python3 -c "import <package>; print('ok')"