Installing on macOS
BurnSim 4 runs natively on macOS, on both Apple Silicon and Intel Macs. It is distributed as a zipped BurnSim.app bundle from the download page.
Installing is just unzip and drag. As of 4.0.0.23, the Mac app is signed with an Apple Developer ID and notarized by Apple, so it opens like any other Mac application - there is no Terminal step and no xattr command. If you are following older instructions that tell you to run xattr -cr, you no longer need to; see Older downloads below.
Which build to download
| Your Mac | Download |
|---|---|
| Apple Silicon (M1, M2, M3, M4 - any Mac from 2020 onward) | the macos-arm64 build |
| Intel | the macos-x64 build |
Not sure which you have? Click the Apple menu > About This Mac. If the Chip line says "Apple M-something" you are on Apple Silicon; if it says Processor and names an Intel chip, you are on Intel.
The Intel build does run on Apple Silicon through Rosetta 2, but there is no reason to choose it there - the arm64 build is native and faster.
BurnSim requires macOS 11 (Big Sur) or later.
Installing
- Download the zip for your Mac and unzip it. Use Finder - double-clicking the zip is enough.
- Drag BurnSim.app to your Applications folder.
- Double-click BurnSim.app.
That is the whole process. The first launch may pause for a second or two while macOS verifies the app with Apple; after that it opens immediately.
Unzip with Finder rather than a third-party tool. The signature covers extended attributes that some unzip utilities silently discard, and a bundle that loses them can be reported as damaged even though the download was fine.
Upgrading from an older version
Drag the new BurnSim.app to Applications and replace the existing one. Your propellants, settings and license are kept - they live outside the app bundle (see below), so replacing the app does not touch them.
If BurnSim will not open
With a notarized build these messages should not appear. If one does, something is genuinely wrong rather than expected, and we would like to hear about it - please get in touch and quote the exact wording.
| Message | What it means | What to do |
|---|---|---|
| "BurnSim is damaged and can't be opened. You should move it to the Trash." | Gatekeeper could not validate the bundle. On a notarized build the usual cause is an incomplete or corrupted download, or an unzip tool that discarded the metadata the signature depends on. | Do not move it to the Trash. Delete the copy you have, download again, and unzip with Finder. If it happens a second time, please report it. |
| "BurnSim can't be opened because Apple cannot check it for malicious software", or "the developer cannot be verified" | macOS could not reach Apple to confirm the app, or an older non-notarized copy is being opened. | Check you are online and try again. If you are opening a build older than 4.0.0.23, see Older downloads. |
| "The application cannot be opened" - a bare message naming no developer and not mentioning Apple checking it | The executable permission did not survive unzipping. | Unzip again with Finder. If you must use another tool, chmod +x /Applications/BurnSim.app/Contents/MacOS/BurnSimrestores it. |
On macOS 15 (Sequoia) and later the old right-click > Open trick no longer works for any of these. Where an override is possible at all it is Open Anyway in System Settings > Privacy & Security.
Older downloads (4.0.0.22 and earlier)
Mac builds before 4.0.0.23 were not notarized. macOS tags anything downloaded from the web with a quarantine flag, and Gatekeeper will only clear a quarantined app that carries a paid Apple Developer ID and has been notarized. Those older builds had neither, so macOS reported:
- "BurnSim is damaged and can't be opened. You should move it to the Trash."
with no Open Anyway offered. The download was not corrupt, and the workaround was to clear the quarantine flag by hand in Terminal:
xattr -cr /Applications/BurnSim.app
This is no longer necessary. If you have an older copy installed, replacing it with 4.0.0.23 or later removes the need for it entirely. The step is recorded here only so that people with older downloads, or following older instructions, know what it was for.
Where BurnSim keeps your files
Settings, the propellant database, activity logs and license data are stored under:
~/Library/Application Support/BurnSim/
That folder is left alone when you replace BurnSim.app with a newer version, so your propellants and settings survive an upgrade. To uninstall BurnSim completely, drag BurnSim.app to the Trash and delete that folder.
Reporting a problem
Activity logging is on by default (Settings > Log Activity for Bug Reports). If something goes wrong, send the newest file from
~/Library/Application Support/BurnSim/logs/
together with a description of what you were doing, to burnsim@burnsim.com. Please include your macOS version and whether your Mac is Apple Silicon or Intel.
The Mac builds are newer than the Windows ones and have had less real-world use, so reports are genuinely useful. The Intel build in particular has had less testing on real hardware than the Apple Silicon one, so if you run it we would be glad to hear that it worked as well as that it did not.
See also
- Activating BurnSim - licensing and activation, including offline activation
- Getting Started with a Basic Simulation - your first motor
- FAQ