macOS says the app can't be opened

Storage Studio is signed and notarised by Apple, so a complete download from storagestudio.us opens normally. If macOS refuses to open it — saying it's damaged, can't be checked, or isn't supported on this Mac — the download is most likely incomplete or altered, or the Mac has an Intel processor. Download it again rather than overriding the warning.

Likely causes

• The download is incomplete or was changed on the way. macOS checks the app's signature when you open it. If any part of the app doesn't match, it won't open — this is the safety check working.
• It's running from the disk image or your Downloads folder instead of your Applications folder.
• The Mac has an Intel processor. Storage Studio 4.18 and later need a Mac with Apple silicon. Intel Macs stay on version 4.17.1, and a newer version won't open on them.
• A copy came from somewhere other than storagestudio.us, such as a file shared by someone else.

%% caption: What to do when macOS won't open Storage Studio
flowchart TD
  A[macOS won't open Storage Studio] --> B{Does this Mac have Apple silicon?}
  B -->|No, Intel| C[Use Storage Studio 4.17.1]
  B -->|Yes| D[Delete the copy that won't open]
  D --> E[Download again from storagestudio.us]
  E --> F[Drag it into Applications]
  F --> G[Open it from Applications]
  G --> H{Opens?}
  H -->|Yes| I[Done]
  H -->|No| J[Get in touch - do not override the warning]

How to fix it

1. Check your Mac's chip. Choose About This Mac from the Apple menu. If it lists an Intel processor, you need Storage Studio 4.17.1 — see Apple silicon and Intel Macs. An Intel Mac that already has 4.17.1 isn't offered updates it can't run.
2. Delete the copy that won't open, including any copy left in your Downloads folder.
3. Download Storage Studio again from storagestudio.us.
4. Open the disk image, drag Storage Studio into Applications, then eject the disk image.
5. Open Storage Studio from your Applications folder. The first time, macOS asks you to confirm you want to open an app downloaded from the internet — that's normal for any downloaded app.

Why we say don't override the warning

macOS offers ways to open an app it has refused. Please don't use them for Storage Studio. A genuine download never needs it, so a refusal means the copy you have isn't the one we published. Getting a fresh copy is quicker and safer than finding out what changed.

If a fresh download from storagestudio.us still won't open on a Mac with Apple silicon, please get in touch — see Getting help.

See also: Installing Storage Studio · Is Storage Studio safe to install? · Apple silicon · Something's not working: start here