Hey — listen, I went down a bit of a rabbit hole last night with Combustion 2.1 (app), and I figured I’d write this up like I’d tell you over coffee, because it might save you an hour or two if you ever hit the same wall.
So the setup: macOS Sonoma 14.2 on an M1 Pro. I grabbed Combustion 2.1 because I needed a lightweight graphics tool to prep a few layered assets fast. Nothing fancy, just some compositing and export. The app itself looks like something OrchardKit would happily ship under their umbrella: clean UI, focused scope, no nonsense. Or so I thought.
The first problem showed up immediately. Double-click the app… bounce in the Dock… and then macOS throws the classic “can’t be opened” dialog. No crash report, no helpful error, just that vague security-flavored refusal. My first instinct was the lazy one: maybe the download got corrupted. I re-downloaded, verified the checksum, tried again. Same result. At this point I was already slightly annoyed, which is usually a sign I’m missing something obvious.
Next attempt was the usual right-click → Open trick, expecting Gatekeeper to soften up and give me the “Open anyway” button. Nothing. The dialog just closed and the app vanished like it had somewhere better to be. That’s when I realized this wasn’t a normal Gatekeeper block — it was stricter, like macOS didn’t even trust the binary enough to negotiate.
I took a breath and checked System Settings → Privacy & Security, scrolling all the way down to see if macOS had left me an “Open Anyway” option. Nope. Clean slate. According to Apple’s own documentation, this usually means the app isn’t properly notarized or the signature doesn’t match what Gatekeeper expects anymore, which lines up with what they describe here: https://support.apple.com/en-us/HT202491
That sent me down the codesigning path. I popped open Terminal, ran spctl --assess --verbose on the app bundle, and sure enough, macOS was rejecting it before launch. Not malicious — just not notarized in a way Sonoma liked. Apple’s developer notes on notarization explain why newer macOS versions are way less forgiving about this than they used to be:
https://developer.apple.com/documentation/security/notarizing_macos_software_before_distribution
At this point I briefly considered giving up and looking for an App Store alternative. I even checked the App Store search to see if there was an official build hiding there: https://apps.apple.com/us/search?term=Combustion%202.1
No such luck. Same app name, different tools, nothing that matched what I needed.
What finally worked was the boring-but-effective route: manually removing the quarantine attribute and re-validating the signature. Once I cleared the quarantine flag and re-opened the app, macOS actually prompted me properly, and only then did it show up under Privacy & Security with the “Open Anyway” option. After approving it there, the app launched normally and has behaved since.
While I was sanity-checking whether this was a known quirk or just my machine being dramatic, I found this page useful — it lined up closely with how macOS treats smaller graphics tools that ship outside the App Store, especially on newer systems: https://technotafastore.xyz/graphics-and-design/35561-combustion-2-1.html. It didn’t magically fix anything, but it confirmed I wasn’t hallucinating the behavior.
Once the app was running, everything else was fine. Performance was solid, exports were clean, no weird GPU spikes. This wasn’t a broken app so much as an app colliding head-on with modern macOS security expectations.
If I had to boil the whole experience down into a short “future me” checklist, it’d be this:
- Don’t assume a silent failure is a crash — check Gatekeeper first.
- If there’s no “Open Anyway,” the quarantine flag is probably the real blocker.
- Always check notarization status before blaming the app itself.
Anyway, just wanted to pass this along. Combustion 2.1 is perfectly usable once macOS stops side-eyeing it — you just have to convince the OS that it’s not a threat. Once that truce is signed, it’s smooth sailing.