You double-click an app and macOS stops you cold: "“[App]” cannot be opened because Apple cannot check it for malicious software." Your only button is often just Move to Trash or Cancel — no obvious way to open it.
Good news: this almost never means the app has a virus. It means the app isn’t notarized, and macOS’s Gatekeeper is being cautious. Below is what the message really means and the safe, in-order way to open an app you actually trust — plus a check to make sure you should.
What this message actually means
Since macOS Catalina, Apple asks developers to notarize their apps — upload them to Apple so they can be scanned for known malware and stamped as checked. When you open an app that was not notarized (or the notarization ticket can’t be read), macOS can’t confirm it’s clean, so it shows: "cannot be opened because Apple cannot check it for malicious software."
Key point: "cannot check" is not the same as "found malware." Apple simply hasn’t seen this exact app build. Plenty of legitimate free and open-source apps are unnotarized. The warning is a caution, not a verdict.
You’ll see closely related wording depending on your macOS version — "macOS cannot verify the developer" or "app is damaged and can’t be opened." The fixes below apply to all three.
Before you override: is the app actually trustworthy?
The override steps are safe only if the app is safe. Bypassing Gatekeeper on a random download is exactly how Macs get infected. Ask yourself first:
- Where did it come from? The developer’s own website or a reputable open-source project (GitHub, Homebrew) is fine. A pop-up, a torrent, a "codec" or "Flash update," or an email attachment is not.
- Were you expecting an installer? If a document or web link suddenly produced an app, stop.
- Does the name match? Random letters, or a real app’s name misspelled, is a red flag.
If anything feels off, don’t override — click Move to Trash. When in doubt, leave it out.
Fix 1 — Right-click, then Open (try this first)
The safest bypass, and it keeps Gatekeeper on for everything else:
- Find the app in Finder (in your Applications folder or wherever you downloaded it).
- Right-click (or Control-click) the app and choose Open.
- You’ll get the same warning — but this time with an Open button. Click it.
macOS remembers your choice, so the app opens normally from then on. If there’s no Open button in the right-click dialog (common on macOS Sequoia and later), use Fix 2.
Fix 2 — System Settings → "Open Anyway"
On recent macOS, Apple moved the override into Settings:
- Try to open the app once (so macOS logs the block) and dismiss the warning.
- Open System Settings → Privacy & Security.
- Scroll to the Security section. You’ll see a line naming the blocked app with an Open Anyway button.
- Click Open Anyway, then authenticate with Touch ID or your password.
This authorizes that one app only — it does not lower your Mac’s security overall.
Fix 3 — Clear the quarantine flag (Terminal, advanced)
Every download gets a hidden com.apple.quarantine tag that triggers this check. Removing it for a specific app you trust stops the prompt. Only do this for an app you’re sure about:
- Open Terminal (Applications → Utilities).
- Type
xattr -dr com.apple.quarantine(with a trailing space), then drag the app onto the Terminal window to paste its path. - Press Return. No output means it worked.
This is safe and reversible — it removes a tag, not any of the app’s files — but it also removes the safety check for that app, so reserve it for software you genuinely trust.
What you should NOT do
Older guides tell you to run sudo spctl --master-disable to turn Gatekeeper off entirely. Don’t. That disables the notarization check for every app on your Mac and leaves you exposed. Use the per-app steps above instead.
Still blocked after all three?
If the app still won’t open, the issue usually isn’t Gatekeeper:
- The app is genuinely damaged. Delete it and re-download from the developer’s official site — a partial download can’t pass the check.
- It’s the wrong architecture. An Intel-only app on Apple Silicon needs Rosetta; a PowerPC-era app won’t run at all.
- Your macOS is too old. Which leads to the real problem…
The bigger picture: a Mac too old to update
If you’re fighting a wall of security warnings and can’t update to a macOS version that supports modern apps, the machine itself is usually the limit. An Intel Mac stuck on an old macOS won’t get Apple’s current security or app compatibility no matter how many flags you clear.
That’s the point where a refurbished Apple Silicon Mac pays for itself. A refurbished M1 MacBook Air starts at $569.99 at LuxuriousComputers — it runs the latest macOS, opens notarized apps without a fight, and every machine ships with our one-year warranty. If budget is the concern, check our Apple clearance deals for the lowest prices we offer. A current M2 Air runs $974.99 and an M3 Air $974.99 — all a fraction of new.
FAQ
Does "Open Anyway" disable my Mac’s security?
No. It authorizes the one app you named. Gatekeeper stays on and keeps checking every other app you open.
Is the app really dangerous if Apple "can’t check" it?
Not necessarily. "Cannot check" means the app wasn’t notarized, not that malware was found. Many legitimate open-source and small-developer apps are unnotarized. Judge it by its source, not by the warning alone.
Is the xattr quarantine command safe?
Yes — it removes a hidden download tag, not any of the app’s files, and only for the app you point it at. Just be sure you trust that specific app first.
I got this on an app from the Mac App Store — why?
App Store apps are pre-checked, so this specific message shouldn’t appear for them. If it does, the download likely got corrupted — delete the app and re-download it from the App Store.