iOS13 crashes instantly for some (EXC_BAD_ACCESS (SIGBUS)

Please provide the following:

  1. SDK Version: 34 (upgrading to 35 now)
  2. Platforms(Android/iOS/web/all): iOS

This is a really strange issue but I’m coming close to exhausting most of the debugging process

For reference: the app was published after Expo released this statement

The issue is that some people (all after updating to iOS13) have the app instantly crash when trying to launch. Sentry doesn’t seem to have enough time to initiate because we don’t see anything for error logging there. The strange thing is we cannot replicate this issue on our end - all of our devices run ios13 fine. The crash issue happens on multiple devices - iPhone X, iPhone 11 (fresh install).

I am unsure how to debug the crash reports but the type is “EXC_BAD_ACCESS (SIGBUS)”

The only thing I found on expo forums that was similar was : but I’m unsure if that’s the issue or not

Because it only happens on some devices and not others (also running the same OS and device) I would imagine it has something to do with a Expo dependency that only some devices use but I am unsure what that would be.

I am in the process of pushing to iOS store with expo 35 right now but I’m still curious as to what was causing this since I’m not sure yet if it fixes it

Any help debugging or anything at all would be greatly appreciated

Thank you!


Having the same issue. Following…

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I know there’s one specific crash caused by calling WebBrowser.dismissBrowser (see, but I wouldn’t expect that to happen immediately on app launch.

We are also facing the same issue “EXC_BAD_ACCESS (SIGBUS)”, it works on some devices and not on others, all running iOS 13.

Would love to help out the Expo Team debug this issue as soon as possible.


I’m also getting users reporting crashes on iOS 13 (with SDK 33) without any Sentry traces showing up; how did y’all identify EXC_BAD_ACCESS (SIGBUS) in the crash?

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The fishhook.c file was removed in SDK 35, so upgrading and rebuilding would work.

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All - we pushed out a fix for this issue on Friday as soon as we discovered it affected users of iOS 13.0 (we previously thought it was exclusive to the iOS 13.1 beta). You can get the fix on SDK 33 or 34 by just rerunning expo build:ios. You’ll need to resubmit to the App Store after that, but upgrading to SDK 35 is not required for this fix. Apologies that we didn’t get this out sooner :disappointed:


esamelson thank you for explanation. Can you please tell us in what exact time and in what UTC offset this fix was released on Friday?

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@serhiipalash the fix was deployed to our production builders at 17:04 PDT (UTC -7) Friday, Sept 20. Any builds started after that time should have the fix.


I can verify that upgrading to SDK 35 has fixed the issue. Thanks everyone!


One of the best solutions to resolve the issue is to completely reset your iPhone and start fresh. Sometimes files/data from the older firmware version conflicts with the newer/updated firmware version and resetting the device removes such conflict visit here.

Can you share more details about the cause of the issue please?

Do we need to bump the build number?
Do we need to bump the version number?

One follow up: our users are seeing what sounds like the opposite of the versions listed above:

App is based on SDK 33

  • app works on 13.0
  • app crashes on 13.1 released version

Seeing crashes on iPhone X upon app launch with SDK 35 running iOS 13.1

Creating a new binary with expo build:ios that has been built after 17:04 PDT (UTC -7) Friday, Sept 20. and submitting it to the App Store should resolve the issue. Is that not the case @daily-h and @chownation?

@adamjnav We were under the impression from @ide 's comment that SDK 35 from release should have that fixed? We did our build before the time frame posted but don’t know yet if it’s an issue on iOS 13.1. Can someone confirm?

Thank you

The fishhook-related crash was fixed in SDK 35 from release. There may be other crashes, in which case please create a separate thread if there is a separate cause so we don’t conflate multiple different issues that share the same symptom.

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@adamjnav Will test tomorrow with TF hosted Expo build on iOS device. Seems sporadic at this point. Watching the AppStore Crashes metric on delay not super helpful. Am I missing another place / way to monitor crashes?

I am getting error reports from users on iPhone 11 or iPhone 11 Pro about the app crashing. They said running iOS 13 on an older device iPhone X works fine. Submitted a new build and hopefully this will fix things.

Build was from yesterday so perhaps not caused by fishhook issue (@ide); tested on both iPhone X and iPad running iOS 13.1 with SDK 35 and seeing same result. What else would be helpful to provide for debugging? The crash logs indicate same symptom “[EXC_BAD_ACCESS (SIGBUS)]”