Many Mac users experienced app slowdowns during the launch of Big Sur, possibly due to issues with Apple's OCSP service being unable to validate certificates

Even Macs that didn't upgrade to Big Sur had problems. — Mac users today began experiencing unexpected issues …

Ars Technica 2020-11-13

Context & Ripple Effects

The Big Sur launch turned a background security mechanism into a visible failure: Apple's OCSP responder, which validates Developer ID certificates for Mac apps, could not keep up, and slowdowns hit even machines that never installed the new OS. Security Embedded's deep dive into the OCSP responder framed the problem as structural — the service is critical to macOS app integrity but operates with little transparency.

The outage has a precedent in Apple's own history: in 2015, an expired certificate temporarily broke Mac App Store apps, showing that centralized trust infrastructure is a recurring single point of failure. The difference this time is that the checks now run constantly in the background of every Mac, not just at install time.

First-order effects

Mac users — including those who stayed on older macOS versions — saw apps hang at launch because each app's Developer ID certificate check depended on Apple's overloaded OCSP service.
Apple's own launch of Big Sur was undermined by its verification layer: the OS update and the certificate-validation outage arrived together, compounding perceived instability.

Second-order effects

The outage exposed what the checks send back: because OCSP requests included identifiable data, the incident fed directly into the privacy scrutiny that pushed Apple to stop logging IP addresses and commit to an encrypted OCSP protocol.
Developers whose apps were wrongly suspected of being slow or broken faced support burdens during the launch window, since the failure surfaced inside their software rather than in Apple's service.

Third-order effects

If every Mac app launch depends on a live call to one vendor's infrastructure, Apple's certificate-checking service becomes a systemic dependency for the entire Mac software ecosystem — an availability and privacy obligation, not just a security feature.
The episode strengthens the case that platform gatekeepers' trust infrastructure needs external transparency: independent analysis of the responder is what turned a slowdown into accountability for data logging and a redesign commitment.

The trend: Centralized app-verification infrastructure at platform gatekeepers is becoming a systemic dependency whose failures — and privacy trade-offs — increasingly surface as user-facing incidents.

Discussion

@lapcatsoftware Jeff Johnson on x
Hey Apple users: If you're now experiencing hangs launching apps on the Mac, I figured out the problem using Little Snitch. It's trustd connecting to https://ocsp.apple.com/ Denying that connection fixes it, because OCSP is a soft failure. (Disconnect internet also fixes.) https:…
@panic @panic on x
😅 Looks like, when apps are launched, Gatekeeper is unable to check their validity over the internet, due to overwhelmed Apple servers. So, uh, let's all hang in there! You got this, Apple devops!
@nixcraft @nixcraft on x
Unimaginable. macOS unable to open any non-Apple application. The joy of Proprietary software. MacOS sends hashes of every executable to Apple server when trustd and syspolicyd cannot do so. The entire macOS stops working. https://twitter.com/...
@minotauruk Chris Bagnall on x
The huge privacy elephant in the room here is the implication that Apple gets a timestamped call home telling them exactly what program you are running whenever you start one. That's not cricket. There needs to be a way of turning this shite off. https://twitter.com/...
@patrickwardle Patrick Wardle on x
On Big Sur, trustd is in Apple's “ContentFilterExclusionList” ....meaning firewalls can't block it! 😭 Welcome to the future? 😱 https://twitter.com/... https://twitter.com/...
@sdw Sebastiaan de With on x
@saradietschy seems like macOS' gatekeeper can't verify stuff, so it just... hangs. :( https://twitter.com/...
@zollotech Aaron Zollo on x
It fully downloaded and then this happened on iMac Pro. It happened at the same time on another Mac. Server restart on Apples side maybe? https://twitter.com/...
@sdw Sebastiaan de With on x
Apple servers are melting a little bit right now. Can cause some hanging issues on your Mac: https://twitter.com/...
@panzer Matthew Panzarino on x
Welp. Love to peg my cpu trying to type because apps are hammering apple servers asking for authorization to open. https://twitter.com/...
@stevebellovin Steven M. Bellovin on x
This explains a lot of what I was seeing this afternoon... https://twitter.com/...
@mattsheffield Matthew Sheffield on x
As macOS Big Sur launched, users' Macs slowed—even those that weren't upgrading https://arstechnica.com/... https://twitter.com/...
@dkiesow Damon Kiesow on x
On two separate Zoom calls we thought the Matrix was glitching because everyone's laptops were crashing simultaneously. No, just Apple: https://twitter.com/...
@emu4ios @emu4ios on x
This is a similar reason to why the date trick (+ others) worked. Usually OCSP falls to “allow” if it can't connect. https://twitter.com/...
@vijayshekhar Vijay Shekhar Sharma on x
In case you weren't able to join Zoom calls from your Mac (like me), this is the reason. https://twitter.com/...
@mitsuhiko Armin Ronacher on x
Holy shit this big sur update must be the worst upgrade experience I have observed. The mac I tried to update to is basically failing to install the update after an awfully slow download and my other mac is now having issues with trustd spinning when I launch apps. The hell apple
@patrickwardle Patrick Wardle on x
...what if the macOS Software Update process, depends on Apple Maps to get routing directions to end users computers!? 🤔🤯 https://twitter.com/...
@arrington Michael Arrington on x
Did everyone's mac shit the bed today or just mine?
@jcenters Josh Centers on x
Good to know that if Apple has a server hiccup my Mac becomes a paperweight. Time to dust off the ol Linux ThinkPad.
@tapbot_paul Paul Haddad on x
Apple: Let's make all apps on our desktop OS phone home before they launch, what could possibly go wrong?
@johnaugust John August on x
Hey if your Mac is suddenly sluggish it's not just you. https://twitter.com/...
@twostraws Paul Hudson on x
Apple marcom: Let's release major operating system updates at short notice. Apple's servers: Wait, wha—🔥🔥 🔥 https://twitter.com/...
@viticci Federico Viticci on x
macOS Big Sur is out, and it's a major turning point for the Mac. Here's our in-depth review, featuring visual comparisons, third-party apps, and lots more. macOS Big Sur: The MacStories Review https://www.macstories.net/... https://twitter.com/...
@johnvoorhees John Voorhees on x
Something to read while you wait for that download... https://twitter.com/...
@flyosity Mike Rundle on x
Just upgraded my main machine to Catalina last week, thinking about scheduling my Big Sur upgrade for approximately 12-15 months from now. You guys are clearly more risk tolerant than I am 😂
@johnvoorhees John Voorhees on x
One more tidbit on Big Sur's design. I know it's not to everyone's tastes, but I think it's fantastic and exactly what the Mac needs for the road ahead. macOS Big Sur: The MacStories Review https://www.macstories.net/... https://twitter.com/...
@stroughtonsmith Steve Troughton-Smith on x
You gotta hand it to Apple's third-party dev community to have so many apps Apple-Silicon-native right out of the gate, including beta versions of Microsoft Office. There was always this idea of the ‘app gap’ for Microsoft & its modern efforts, but maybe it's just a developer gap
@stroughtonsmith Steve Troughton-Smith on x
Speaking of shipping at scale, Apple has now shipped the Apple Silicon versions of its iWork suite, Garageband, Final Cut Pro, Logic, Motion, and Xcode. Compare and contrast with how other platforms have handled their ARM transitions... 🦗🎶 https://twitter.com/...
@johnvoorhees John Voorhees on x
Big Sur is a really big deal; a turning point in the Mac's history that doesn't come along very often. I spent the last several months testing it and here's my review on @Macstoriesnet: Big Sur: The MacStories Review. I hope you enjoy it. https://www.macstories.net/... https://tw…
@backlon Dieter Bohn on x
One of my biggest frustrations with Big Sur is that Safari STILL does not allow you to set a websites as a single site browser / web app / separate window. Chrome and Edge let you do this right in the browser, with Safari you have to resort to third party tools.
@backlon Dieter Bohn on x
Once upon a time the default advice was don't upgrade on day 1 because your apps may not work. For the past few years that wasn't really a probem. This year ... I would wait. I've had at least a couple of my bipbobs not work or work oddly on Big Sur. It's okay to wait! https://tw…
@ifenixx @ifenixx on x
macOS 11 Big Sur now available!! 🔥🔥 2015 and later MacBook 2013 and later MacBook Air 2013 and later MacBook Pro 2014 and later Mac mini 2014 and later iMac 2017 and later iMac Pro 2013 and later Mac Pro https://apps.apple.com/...
@jonyiveparody @jonyiveparody on x
You go first, I'll wait here... https://twitter.com/...
@mantia Louie Mantia, Jr on x
why in the mac app store is there a human hand touching macos interface elements https://twitter.com/...
@gruber John Gruber on x
Ben's wrongheaded stance on touchscreen Macs is the gift that keeps on giving, if you worry that he and I agree on too many topics. https://twitter.com/...
@stroughtonsmith Steve Troughton-Smith on x
@gruber Whether it should support finger touch or not, the iMac should definitely have a design that supports Apple Pencil, like Microsoft's Surface Studio
@neilcybart Neil Cybart on x
Consensus in many tech circles was that Apple would never ever transition the Mac to its own silicon. Something to keep in mind when consensus solidifies around the next Mac-related topic.
@arnoldkim Arnold Kim on x
Been a long time since I've seen excitement around Mac benchmarks. The “waiting for PowerBook g5” days were long ago. Feels a bit like old times.
@neilcybart Neil Cybart on x
One of the more fascinating things with the Mac is how there is always that tension in the air between long-time users and Apple. It never goes away. You don't see a similar tension with any other Apple product category and corresponding user group.
@stevesi Steven Sinofsky on x
@benedictevans It should (will be) added but the utility for desktop apps will be nil. The real benefit to users and developers is for iPad and iPhone apps, many of which will never get tuned for mouse/keyboard which could be a lot of work for small number of users.
@markgurman Mark Gurman on x
Have to believe at this point not putting touch on the Mac is influenced by not wanting to hurt iPad sales. Why would Apple make a hybrid when they can sell you both? https://twitter.com/...
@choco_bit Fudge on x
There's a lot of jumping to conclusions with those M1 benchmarks atm and it's kinda sad. Wait a week or 2 for proper real world based tests to come out and don't rely on worthless ones like geekbench
@federighios Craig Federighi Parody on x
Don't assume the MacBook Air will be silent just because it's fanless. Big Sur will play audio of spinning fans through the speakers during heavy workloads.
@tapbot_paul Paul Haddad on x
Before you run out and get the latest shiny just remember. 1. 16GB of RAM, you can live with it, but do you want to? 2. There will be software that won't work right away. 3. You'll have to use Big Sur version .0. 4. Apple almost has to release a M1X sometime early next year.
@markgurman Mark Gurman on x
The ergonomics argument went out the window when they launched the Smart Keyboard for the iPad Pro 5 years ago. The macOS isn't optimized for touch argument somewhat went out the window with Big Sur. I think we're almost out of other reasons.
@dcominottim @dcominottim on x
I absolutely love the mindshare Apple's M1 & Arm are getting. The knowledgeable can scream all they want at the marketing, but if they were *wise*, they'd realize the effects prove Apple's marketing did a textbook move. And, thankfully, their narrative has obsoleted “MOAR CORES.”
@jonmasters @jonmasters on x
@stephentyrone First gen part puts entire industry to shame instantly. I would imagine Apple don't plan to stay still. It'll be like playing Mario Kart when the other player is a whole lap ahead and you're wondering if they're still there
@ganeumann @ganeumann on x
I don't understand people who want Apple to put touch screens on their laptops. I have a laptop with a touch screen and I've never used it on purpose, but touch it accidentally while typing all the time
@_andrew_griffin Andrew Griffin on x
Also: no touchscreens. https://twitter.com/...
@_andrew_griffin Andrew Griffin on x
Includes this moment of Craig Federighi admitting Apple didn't actually think the computers were going to be this fast: https://twitter.com/...
@_andrew_griffin Andrew Griffin on x
Don't call the ARM transition boring https://twitter.com/...
@_andrew_griffin Andrew Griffin on x
Apple just revealed perhaps the most important change to its Macs, ever. I spoke to some of its most important people about how and why: https://www.independent.co.uk/ ...
@reneritchie Rene Ritchie on x
Nobody remembers to disable/prevent/opt-out automatic uploads to Geekbench when testing new hardware. Nobody. 😂 https://twitter.com/...
@benedictevans Benedict Evans on x
The problem with the Surface Studio: how many pro apps that you run on a $5k PC are rewritten for touch? Photoshop? Autocad? You can add a bit, but do you rewrite the whole UI? And for one low-volume PC? So: if Apple does add touch to the Mac, how many apps get redesigned for it?
@benedictevans Benedict Evans on x
It seems quite possible Apple will add touch to the Mac. This is a religious debate as much as an analysis. But if the first Apple Silicon iMac has touch, how does that work? Maybe it has a hinge... like this? https://twitter.com/...
@stroughtonsmith Steve Troughton-Smith on x
The only reason anybody is complaining about the 16GB RAM limit in Apple's new low-end M1 machines is that all the high-end-Mac people want them so bad. When the higher-end machines ship, they'll be *even faster* & more powerful — you just gotta wait 😂

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