Install On MacOS.command Not Opened In SMAPI? How To Fix It On Mac

You just downloaded SMAPI to add mods to Stardew Valley on your Mac. You click the install on macOS.command file. Instead of the install window you wanted, macOS stops you. A warning pops up. It says the file was not opened. Apple says it cannot check the file for harmful code. If this sounds familiar, you are not alone. Many Mac users hit this wall. The fix takes just a few clicks once you know where to look.

This article covers every reason SMAPI will not open on a Mac. It also gives you the exact clicks that fix each one.

Table of Contents

What Is SMAPI, and Why Does macOS Block It?

SMAPI stands for Stardew Modding API. It loads mods into Stardew Valley. It does not touch the game’s own files. Without SMAPI, code mods cannot run at all.

Here is the catch. Apple did not make SMAPI. You did not buy it from the App Store. So macOS treats it as an unknown file. Apple uses a tool called Gatekeeper. Gatekeeper blocks apps and scripts it cannot check. The install on macOS.command file trips this tool every time. That is why the warning shows up on new Macs and old Macs alike.

Why You See “Install on macOS.command Not Opened”

This warning means macOS blocked the install before it even ran. It has nothing to do with your internet speed. It has nothing to do with a broken zip file. macOS is just refusing to run a script it cannot trust yet.

The fix is not to click the file open again and again. You need to tell macOS, in its own settings, that you trust this one file.

How to Fix “Install on macOS.command Not Opened”

Follow these steps in order.

Download the newest SMAPI file from the official site. Extract the zip file. Keep the new folder outside your Stardew Valley game folder.
Right click the install on macOS.command file. Choose Open. Do not double click it.
When the warning box shows up, click Done.
Open System Settings on your Mac.
Go to Privacy and Security. Scroll down to the Security part near the bottom.
Look for a line that says the file was blocked to protect your Mac. Click Open Anyway.
A second warning box will pop up. Click Open Anyway one more time.
Type your Mac password. Press Enter.

The install script should now open in Mac Terminal and start running. If you have never used Terminal before, that is fine. You do not need to type a single word. Just follow the short lines on the screen.

Fix the “SMAPI Is Malware” Warning

Some Mac users get a stronger warning. It calls SMAPI outright malware instead of a blocked file. Apple made its scan rules stricter, so this warning needs one more round of settings first.

Restart your Mac. Do not skip this step. Skipping it is the top reason this fix fails.
Open System Settings. Go to Privacy and Security.
Look for Developer Tools in the list. If you do not see it, open Terminal through Spotlight. Press Command and Space, type Terminal, then hit Enter. Run this line: spctl developer-mode enable-terminal
Click Developer Tools. Turn on the switch next to Terminal. If you use iTerm or the Stardrop mod manager, add those too.
Restart your Mac again.
Open install on macOS.command the same way as before.

If Steam is open while you do this, close it first. You can force quit apps on Mac the same way you close any stuck program. Then start the installer again once Steam is fully shut down.

Fix “Operation Not Permitted: ‘internal'”

A different error may show up. It says Operation not permitted internal. This means Terminal does not have the access it needs.

Open System Settings, or System Preferences on older Macs.
Go to Security and Privacy. Click the Privacy tab.
Scroll to Full Disk Access.
Click the lock icon. Type your password to make changes.
Click the plus button. Add Terminal to the list.
Run install on macOS.command again.

The Game Opens, But Mods Still Don’t Load

Sometimes the installer finishes with no errors. Yet Stardew Valley still opens with no mods. This almost always comes down to how you launch the game.

Always start Stardew Valley through Steam. Do not open the app icon by itself. Steam checks and repairs game files in the background at times. That check can undo a manual install if you swapped files by hand instead of using the real installer. Running the install on macOS.command file avoids this problem, since the installer keeps track of what it changes.

You also do not need to touch your Steam launch options on a Mac. That step is only for Windows.

While you check your Steam library for the issue, take a minute to check for hidden games on Steam too. You may own copies you forgot about, and a messy library can make it harder to spot the right game file.

A Quick Checklist Before You Try Again

Your Mac runs macOS 10.15 or newer.
The SMAPI zip file is fully extracted, not still zipped.
The new folder sits outside your Stardew Valley game folder.
You right clicked the file and chose Open, not double click.
Developer Tools is turned on for Terminal.
Terminal has Full Disk Access.
Steam is fully closed before you run the installer.
You launch the game through Steam once SMAPI is in place.

Did you check every box above, and install on macOS.command still will not open? Restart your Mac one more time. That step clears out a lot of stuck permission issues. In rare cases, a hardware level reset can help too. If your Mac keeps acting oddly after all these changes, try to reset your Mac’s SMC before you run the installer again.

Frequently Asked Questions

Can I install SMAPI without using Terminal at all?

Not fully. Terminal opens on its own when you run install on macOS.command. You do not need to type commands into it yourself, unless macOS blocks Developer Tools access first.

Do I need to change my Steam launch options on Mac?

No. Steam launch options are a Windows only step. On a Mac, SMAPI installs right into your game folder. Launching through Steam is all you need.

Why does macOS keep blocking the file even after I click Open Anyway?

This often means the warning showed up twice, but you only clicked once. macOS shows a second box right after the first one. Both need a click before the password prompt shows up.

Is it safe to install SMAPI despite the malware warning?

Yes. SMAPI is a well known, open tool built by the Stardew Valley mod community. It has been used safely for years. macOS flags it because Apple has not reviewed or signed it, not because it holds harmful code.

Conclusion

Getting past install on macOS.command not opened takes patience, not computer skill. Once Terminal has the access it needs, and Steam is closed during setup, the installer finishes in under a minute. From there, mods load on their own each time you start the game through Steam. You will not need to repeat these steps again unless you update to a new SMAPI version.

Harris K.

Harris loves digging into software to find what others miss. He has a real passion for sharing Tricks and Hidden Features that simplify your digital life. He writes these guides to help you get more done with less effort.