“MCA not working on Mac” (issue #348) is one of the most discussed threads in the project’s history — and also one of the most outdated. Most of the advice in old threads describes wrestling a bare .jar plus a hand-installed JavaFX on macOS. That route is obsolete: there is an official Mac package now, and starting there fixes the majority of cases.
The current way to install on Mac
- Download the macOS .dmg that matches your chip from the download page:
arm64for Apple Silicon (M-series) Macs,x64for Intel Macs. These official .dmg packages have existed since MCA Selector 2.8; the current release is 2.9. - Open the .dmg and install the app as you would any other.
- Launch it. Because it is a self-contained app, you do not need to install Java or JavaFX separately for the packaged build.
Our full walkthrough, including how to tell which chip your Mac has, is the MCA Selector for Mac install guide.
If macOS refuses to open it (Gatekeeper)
macOS Gatekeeper can block apps that did not come from the App Store, sometimes with a warning that the app “cannot be opened” or is damaged — wording that sounds worse than it is. The standard way through it:
- Instead of double-clicking, right-click (or Control-click) the app and choose Open. macOS then shows the same warning but with an Open button — confirming once is usually enough for future launches.
- If there is no Open button, go to System Settings → Privacy & Security, scroll to the note about the blocked app, and choose Open Anyway.
- Only do this for the genuine package: verify you got the .dmg via our download page, which links the official GitHub release and lists its SHA-256 checksum.
If you are following an old guide that uses the .jar
Old threads (including much of #348) assume the universal .jar plus a manually installed JavaFX. On macOS that combination fails in exactly the ways those threads describe — missing-JavaFX dialogs and silent launches — and debugging it is no longer worth your time now that a native package exists. Switch to the .dmg for your chip first; keep the .jar route only if you specifically need it, in which case our Missing JavaFX guide has the official module-path launch command.
If it still does not work
Confirm the two basics first: the .dmg matches your chip (an x64 build on Apple Silicon, or vice versa, causes exactly this class of failure), and you are on the current version rather than an old download. If both are right, open the world folder check from our No Dimensions Found guide if the app opens but the world will not — that error is about folder selection, not about Macs. For install failures beyond that, issue #348 on the official tracker is the thread to read and add your macOS version and chip to.
Get the Current Version First
Several of the problems in this guide disappear on the current release. MCA Selector 2.9 is free and open source — get the Windows installer, the cross-platform .jar, the macOS .dmg or the Linux .deb/.rpm from the MCA Selector download page, where every button points at the official GitHub release files with their SHA-256 checksums.
More troubleshooting
This page is part of our MCA Selector troubleshooting hub, which groups every known launch, loading and editing problem by symptom.