OSFT Launcher not opening on your Mac? Fix it step by step

You double-click OSFT Launcher and nothing useful happens: a security warning, an engine bar frozen at the same percentage, or a license key the app keeps rejecting. Before hunting for something exotic, work out which failure you are actually looking at, because they are fixed in completely different places. There is also a fourth case that is not a failure at all: if it is Teamfight Tactics itself that no longer starts on your Mac, nothing on your machine is broken. TFT dropped macOS support in patch 18.1, and the desktop client you used to open simply stopped existing on that system. If you have not installed the launcher yet, start with our step-by-step install tutorial instead: this guide is for when that install went sideways.

Four failures that look alike and are not

The visible symptom tells you very little. "It does not work" covers causes that have nothing in common, so the first sort is by the moment things stop, and it saves most of the time.

• The app never opens: macOS throws a security warning and closes the window. That is a system setting, not a defect in the launcher.
• The app opens but stalls: the engine install stops progressing, or the license key is refused. Those two cases cover most support tickets.
• Everything is installed but the game will not start: black screen, back to the desktop, a match that never loads. That is the last third of the road, usually a Google account or an unfinished download.
• And the case that is not a failure: the macOS client of TFT stopped launching with patch 18.1. No reinstall brings it back.

That last point deserves saying once, clearly. Patch 18.1 opens Set 18 and moves the game onto Unreal Engine, and it removes macOS support along the way: no support, no fixes. Riot calls the removal temporary and says it is working to support the system in a future update, with no date announced. Nothing happens to your account in the process: progression, rank and purchases stay tied to your Riot account, and the Android version remains fully supported. That Android build is exactly what OSFT Launcher runs. The full story is in our article on the macOS removal.

Three checks that resolve half the cases

1. 1The chip: Apple menu, About This Mac. It has to read Apple M1, M2, M3 or M4. An Intel Mac cannot run the launcher and no setting will change that; the alternatives are laid out in our guide for Intel Macs.
2. 2The macOS version: macOS 12 (Monterey) at minimum, shown in the same window. On an older system the app may open and then fail further down the line, which produces misleading symptoms.
3. 3Free disk space: budget around ten gigabytes for the engine and the game. An almost full drive is the single most common reason an install looks frozen halfway. The full requirements live in our TFT on Mac system requirements guide.

macOS refuses to open the app

The message reads roughly like "the application cannot be opened because the developer cannot be verified", and the dialog mostly offers to move the file to the Bin. That is not a verdict on the launcher: macOS treats every app downloaded outside the App Store this way until you open it explicitly once. The fix takes ten seconds.

1. 1Drag OSFT Launcher into the Applications folder first. An app launched from its disk image or from the Downloads folder runs from a temporary location where its files do not persist between sessions.
2. 2Then right-click it and choose Open from the menu: the same dialog returns, this time with an Open button. A plain double-click never offers that button.
3. 3If the button is missing, go to System Settings, Privacy and Security, scroll to the message naming OSFT Launcher and click Open Anyway. You grant that permission once.
4. 4After a major macOS update the dialog may show up one more time. That is expected, and the answer is the same.

The launcher opens but the engine install stops moving

On first launch OSFT Launcher installs its engine, the component that runs the Android environment locally. That is a multi-gigabyte download followed by an extraction: a few minutes of apparent silence are normal, and the bar can sit at the same spot while data is written to disk. What is not normal is a bar that has not moved at all after half an hour. Four causes cover nearly everything.

• Disk space: check the real free space during the install, not before it. macOS sometimes counts local snapshots as available space, and that space is released slowly.
• Sleep: a Mac that dozes off mid-download interrupts it. Keep the screen awake for the duration of the first install.
• The network: a VPN, a corporate firewall or a campus network frequently blocks large downloads. Try a home connection, or tether from your phone.
• Third-party antivirus: those tools scan every file written and can slow the install enough to make it look dead. Pause real-time protection for this step.

If nothing budges anyway, quit the launcher completely (right-click its Dock icon, then Quit), restart the Mac and try again. A cleanly resumed install beats a forced one every time.

The license key is refused

Your key appears on screen right after checkout and goes out by email at the same moment. When the launcher rejects it, the cause is almost always on this list.

• A stray space: copying from an email often drags along a leading or trailing space, sometimes an invisible line break. Paste the key into a blank note to see what you actually copied.
• Autocorrect: macOS may capitalise the first pasted character, or swap two characters for typographic punctuation. Paste as plain text.
• The wrong inbox: if you have two addresses, the key is not in the one you are staring at. Look for the purchase confirmation, not the bank receipt.
• An expired subscription: a key stops validating at the end of the paid period. Resubscribing with the same address restores access.
• A key already active elsewhere: one subscription equals one active Mac. If you changed machines, support releases the old one, and that is quick.

A key is never actually lost: it lives in the purchase confirmation email, and support can retrieve it from the address used at checkout.

Google sign-in fails, or TFT never installs

The launcher installs Teamfight Tactics from the real Google Play, which requires a successful Google sign-in: you get Riot official app, not a file scraped off some third-party site. This is the step where blockers appear that have nothing to do with your Mac. Two-step verification waiting for a tap on your phone, a school or work account restricted by an administrator, a sign-in Google flagged as unusual and put on hold: none of that is solved inside the launcher. A wrong system clock is enough to break authentication too, so make sure date and time are set automatically.

Once you are signed in, the game downloads in the background and can look like nothing is happening. Leave the window open and do not restart the install over and over: two downloads of the same package fight each other and only make the wait longer.

The game launches but the screen stays black

A few seconds of black screen at start-up are expected while rendering initialises and the logo appears. A black screen that lasts is something else. Quit the game and relaunch it once without closing the launcher: the second attempt often succeeds, because the files written during the first launch are finally in place. If the picture comes back but everything stutters, you are no longer facing a start-up problem but a performance one, and the way to tell network lag from a frame rate drop is covered in our guide to lag in TFT on Mac.

What to send support so one reply is enough

A message that says "it does not work" costs two days of back and forth. A message with the six lines below is usually answered once and closed.

1. 1The model and chip exactly as they appear in Apple menu, About This Mac (for example MacBook Air M2, 2022).
2. 2The macOS version, shown in the same window.
3. 3The exact step where it stops: opening the app, engine install, license key, Google sign-in, launching the game.
4. 4The error message word for word, or better, a screenshot (Command, Shift, 4).
5. 5The email address used at checkout: that is what identifies your license.
6. 6What you already tried, so nobody asks you to do it twice.

The contact form on the site exists for exactly this, and the answer lands in the address you give.