IOS app crash when screen protector is ON

[MhmdAlkashif]

Hello Developer,

hope you are well, I found an issue on IOS when I turn on the screen protector and I'm using flutter_inappwebview package, the crash happens when I enter full screen for the video and then change the orientation to landscape right/left

after long investigation I realized that the issue is from the screen_protector package because when I turn it off, it works normally

IOS version -> 26.0
Flutter version -> latest
screen_protector package version -> 1.4.4

it is critical issue in my app and I need to fix it because I can't depend on any other similar package.

contact me anytime at -> m.kashif@abwaab.com

thanks for your understanding

[abdallah-odeh]

Same issue here, this crash is very bad, took me days until I found that this is the plugin causing the crash.

[sanderpensa]

iOS 15.8.5 crashes with version 1.4.4.
Flutter 3.35.7

pod:
ScreenProtectorKit (~> 1.4.0)

Very bad crash, took hours to debug, memory access error.

Stacktrace
libMainThreadChecker.dylibchecker_c:
0x1ea31740c <+0>: sub sp, sp, #0x190
-> 0x1ea317410 <+4>: stp x28, x27, [sp, #0x130]
0x1ea317414 <+8>: stp x26, x25, [sp, #0x140]
0x1ea317418 <+12>: stp x24, x23, [sp, #0x150]
0x1ea31741c <+16>: stp x22, x21, [sp, #0x160]
0x1ea317420 <+20>: stp x20, x19, [sp, #0x170]
0x1ea317424 <+24>: stp x29, x30, [sp, #0x180]
0x1ea317428 <+28>: add x29, sp, #0x180
0x1ea31742c <+32>: mov x20, x1
0x1ea317430 <+36>: mov x19, x0
0x1ea317434 <+40>: adrp x8, 41556
0x1ea317438 <+44>: ldr x8, [x8, #0xb58]
0x1ea31743c <+48>: ldr x8, [x8]
0x1ea317440 <+52>: stur x8, [x29, #-0x60]
0x1ea317444 <+56>: adrp x8, 71146
0x1ea317448 <+60>: ldrb w8, [x8, #0x788]
0x1ea31744c <+64>: cbnz w8, 0x1ea317490 ; <+132>
0x1ea317450 <+68>: bl 0x1e47211dc ; symbol stub for: pthread_main_np
0x1ea317454 <+72>: cbz w0, 0x1ea3174a0 ; <+148>
0x1ea317458 <+76>: ldur x8, [x29, #-0x60]
0x1ea31745c <+80>: adrp x9, 41556
0x1ea317460 <+84>: ldr x9, [x9, #0xb58]
0x1ea317464 <+88>: ldr x9, [x9]
0x1ea317468 <+92>: cmp x9, x8
0x1ea31746c <+96>: b.ne 0x1ea3176c0 ; <+692>
0x1ea317470 <+100>: ldp x29, x30, [sp, #0x180]
0x1ea317474 <+104>: ldp x20, x19, [sp, #0x170]
0x1ea317478 <+108>: ldp x22, x21, [sp, #0x160]
0x1ea31747c <+112>: ldp x24, x23, [sp, #0x150]
0x1ea317480 <+116>: ldp x26, x25, [sp, #0x140]
0x1ea317484 <+120>: ldp x28, x27, [sp, #0x130]
0x1ea317488 <+124>: add sp, sp, #0x190
0x1ea31748c <+128>: ret
0x1ea317490 <+132>: ldr x8, [x19, #0x10]
0x1ea317494 <+136>: add x8, x8, #0x1
0x1ea317498 <+140>: str x8, [x19, #0x10]
0x1ea31749c <+144>: b 0x1ea317450 ; <+68>
0x1ea3174a0 <+148>: bl 0x1ea317f54 ; GetThreadLocalData
0x1ea3174a4 <+152>: ldrh w8, [x0]
0x1ea3174a8 <+156>: cbnz w8, 0x1ea317458 ; <+76>
0x1ea3174ac <+160>: adrp x8, 70890
0x1ea3174b0 <+164>: ldrb w8, [x8, #0x6d9]
0x1ea3174b4 <+168>: cbz w8, 0x1ea3174d0 ; <+196>
0x1ea3174b8 <+172>: adrp x8, 71146
0x1ea3174bc <+176>: ldr x0, [x8, #0x758]
0x1ea3174c0 <+180>: adrp x8, 71146
0x1ea3174c4 <+184>: ldr x1, [x8, #0x768]
0x1ea3174c8 <+188>: bl 0x1e2aa26f8
0x1ea3174cc <+192>: cbnz w0, 0x1ea317458 ; <+76>
0x1ea3174d0 <+196>: adrp x8, 70890
0x1ea3174d4 <+200>: ldrb w8, [x8, #0x6da]
0x1ea3174d8 <+204>: cbz w8, 0x1ea317508 ; <+252>
0x1ea3174dc <+208>: mov x0, x20
0x1ea3174e0 <+212>: bl 0x1ea318304 ; symbol stub for: dyld_image_header_containing_address
0x1ea3174e4 <+216>: mov x8, #0x0 ; =0
0x1ea3174e8 <+220>: adrp x9, 71146
0x1ea3174ec <+224>: add x9, x9, #0x740 ; InlineCallsMachHeaders
0x1ea3174f0 <+228>: ldr x10, [x9, x8]
0x1ea3174f4 <+232>: cmp x0, x10
0x1ea3174f8 <+236>: b.eq 0x1ea317458 ; <+76>
0x1ea3174fc <+240>: add x8, x8, #0x8
0x1ea317500 <+244>: cmp x8, #0x18
0x1ea317504 <+248>: b.ne 0x1ea3174f0 ; <+228>
0x1ea317508 <+252>: mov x0, x20
0x1ea31750c <+256>: bl 0x1ea318310 ; symbol stub for: dyld_image_path_containing_address
0x1ea317510 <+260>: mov x21, x0
0x1ea317514 <+264>: adrp x8, 70890
0x1ea317518 <+268>: ldrb w8, [x8, #0x6de]
0x1ea31751c <+272>: cbz w8, 0x1ea317538 ; <+300>
0x1ea317520 <+276>: adrp x0, 1
0x1ea317524 <+280>: add x0, x0, #0xbc3 ; "/System/"
0x1ea317528 <+284>: mov x1, x21
0x1ea31752c <+288>: mov w2, #0x7 ; =7
0x1ea317530 <+292>: bl 0x1ea3184c0 ; symbol stub for: strncmp
0x1ea317534 <+296>: cbz w0, 0x1ea317458 ; <+76>
0x1ea317538 <+300>: mov x0, x21
0x1ea31753c <+304>: mov w1, #0x2f ; =47
0x1ea317540 <+308>: bl 0x1e93612c8
0x1ea317544 <+312>: cbz x0, 0x1ea31755c ; <+336>
0x1ea317548 <+316>: add x0, x0, #0x1
0x1ea31754c <+320>: adrp x1, 1
0x1ea317550 <+324>: add x1, x1, #0xbcc ; "libMTLInterpose.dylib"
0x1ea317554 <+328>: bl 0x1ea318490 ; symbol stub for: strcmp
0x1ea317558 <+332>: cbz w0, 0x1ea317458 ; <+76>
0x1ea31755c <+336>: adrp x8, 71146
0x1ea317560 <+340>: ldrb w8, [x8, #0x722]
0x1ea317564 <+344>: cbz w8, 0x1ea317650 ; <+580>
0x1ea317568 <+348>: movi.16b v0, #0x0
0x1ea31756c <+352>: stp q0, q0, [sp, #0x100]
0x1ea317570 <+356>: stp q0, q0, [sp, #0xe0]
0x1ea317574 <+360>: stp q0, q0, [sp, #0xc0]
0x1ea317578 <+364>: stp q0, q0, [sp, #0xa0]
0x1ea31757c <+368>: stp q0, q0, [sp, #0x80]
0x1ea317580 <+372>: stp q0, q0, [sp, #0x60]
0x1ea317584 <+376>: stp q0, q0, [sp, #0x40]
0x1ea317588 <+380>: stp q0, q0, [sp, #0x20]
0x1ea31758c <+384>: add x25, sp, #0x20
0x1ea317590 <+388>: add x0, sp, #0x20
0x1ea317594 <+392>: mov w1, #0x20 ; =32
0x1ea317598 <+396>: bl 0x1e624e0c4
0x1ea31759c <+400>: cbz w0, 0x1ea31762c ; <+544>
0x1ea3175a0 <+404>: mov x26, #0x0 ; =0
0x1ea3175a4 <+408>: mov w27, w0
0x1ea3175a8 <+412>: mov w24, #0x1 ; =1
0x1ea3175ac <+416>: adrp x28, 71146
0x1ea3175b0 <+420>: adrp x21, 1
0x1ea3175b4 <+424>: add x21, x21, #0xbe2 ; "NSDocument writeToURL"
0x1ea3175b8 <+428>: adrp x22, 1
0x1ea3175bc <+432>: add x22, x22, #0xbf8 ; "NSDocument writeSafelyToURL"
0x1ea3175c0 <+436>: ldr x0, [x25, x26, lsl #3]
0x1ea3175c4 <+440>: bl 0x1ea318304 ; symbol stub for: dyld_image_header_containing_address
0x1ea3175c8 <+444>: ldr x8, [x28, #0x728]
0x1ea3175cc <+448>: cmp x0, x8
0x1ea3175d0 <+452>: b.ne 0x1ea317618 ; <+524>
0x1ea3175d4 <+456>: movi.16b v0, #0x0
0x1ea3175d8 <+460>: stp q0, q0, [sp]
0x1ea3175dc <+464>: ldr x0, [x25, x26, lsl #3]
0x1ea3175e0 <+468>: mov x1, sp
0x1ea3175e4 <+472>: bl 0x1ea2cb05c ; symbol stub for: dladdr
0x1ea3175e8 <+476>: ldr x23, [sp, #0x10]
0x1ea3175ec <+480>: cmp w0, #0x0
0x1ea3175f0 <+484>: ccmp x23, #0x0, #0x4, ne
0x1ea3175f4 <+488>: b.eq 0x1ea317618 ; <+524>
0x1ea3175f8 <+492>: mov x0, x23
0x1ea3175fc <+496>: mov x1, x21
0x1ea317600 <+500>: bl 0x1e93612d4
0x1ea317604 <+504>: cbnz x0, 0x1ea3176c4 ; <+696>
0x1ea317608 <+508>: mov x0, x23
0x1ea31760c <+512>: mov x1, x22
0x1ea317610 <+516>: bl 0x1e93612d4
0x1ea317614 <+520>: cbnz x0, 0x1ea3176c4 ; <+696>
0x1ea317618 <+524>: add x26, x26, #0x1
0x1ea31761c <+528>: cmp x26, x27
0x1ea317620 <+532>: cset w24, lo
0x1ea317624 <+536>: cmp x27, x26
0x1ea317628 <+540>: b.ne 0x1ea3175c0 ; <+436>
0x1ea31762c <+544>: adrp x8, 71146
0x1ea317630 <+548>: ldrb w8, [x8, #0x722]
0x1ea317634 <+552>: cbz w8, 0x1ea317650 ; <+580>
0x1ea317638 <+556>: adrp x8, 71146
0x1ea31763c <+560>: ldr x0, [x8, #0x760]
0x1ea317640 <+564>: adrp x8, 71146
0x1ea317644 <+568>: ldr x1, [x8, #0x770]
0x1ea317648 <+572>: bl 0x1e2aa26f8
0x1ea31764c <+576>: cbnz x0, 0x1ea317458 ; <+76>
0x1ea317650 <+580>: bl 0x1ea317f54 ; GetThreadLocalData
0x1ea317654 <+584>: ldrb w8, [x0, #0x10]
0x1ea317658 <+588>: cbnz w8, 0x1ea317458 ; <+76>
0x1ea31765c <+592>: ldr x8, [x19, #0x18]
0x1ea317660 <+596>: add x8, x8, #0x1
0x1ea317664 <+600>: str x8, [x19, #0x18]
0x1ea317668 <+604>: adrp x9, 70890
0x1ea31766c <+608>: ldr x9, [x9, #0x6d0]
0x1ea317670 <+612>: cbz x9, 0x1ea31767c ; <+624>
0x1ea317674 <+616>: cmp x8, x9
0x1ea317678 <+620>: b.hi 0x1ea317458 ; <+76>
0x1ea31767c <+624>: adrp x8, 70890
0x1ea317680 <+628>: ldrb w8, [x8, #0x6d8]
0x1ea317684 <+632>: cbz w8, 0x1ea3176a0 ; <+660>
0x1ea317688 <+636>: bl 0x1ea317f54 ; GetThreadLocalData
0x1ea31768c <+640>: ldr x8, [x0, #0x8]
0x1ea317690 <+644>: cmp x8, x20
0x1ea317694 <+648>: b.eq 0x1ea317458 ; <+76>
0x1ea317698 <+652>: bl 0x1ea317f54 ; GetThreadLocalData
0x1ea31769c <+656>: str x20, [x0, #0x8]
0x1ea3176a0 <+660>: bl 0x1ea317f54 ; GetThreadLocalData
0x1ea3176a4 <+664>: mov w8, #0x1 ; =1
0x1ea3176a8 <+668>: strb w8, [x0, #0x10]
0x1ea3176ac <+672>: ldr x0, [x19, #0x8]
0x1ea3176b0 <+676>: bl 0x1ea3166a8 ; ASSERT_API_MUST_BE_CALLED_FROM_MAIN_THREAD_FAILED
0x1ea3176b4 <+680>: bl 0x1ea317f54 ; GetThreadLocalData
0x1ea3176b8 <+684>: strb wzr, [x0, #0x10]
0x1ea3176bc <+688>: b 0x1ea317458 ; <+76>
0x1ea3176c0 <+692>: bl 0x1e2331f80
0x1ea3176c4 <+696>: tbnz w24, #0x0, 0x1ea317458 ; <+76>
0x1ea3176c8 <+700>: b 0x1ea31762c ; <+544>`

[prongbang]

Thanks for reporting the issue. I’ve added logic to prevent creation before any window becomes visible and tested it on a real device. No crash was found, but I’m not completely sure if it’s the exact case you encountered. Please try version 1.4.5 and let me know if it still happens.

[sanderpensa]

Thanks for the update, tried the 1.4.5 version but unfortunately it did not fix the crash on iOS 15.8.5 so we keep using v1.4.3 for now.

Our case when the crash happens:

1. We call a flutter message channel method in AppDelegate.swift (FlutterBasicMessageChannel generated by pigeon) when apns push arrives in the foreground:
   override func userNotificationCenter( _ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (_ options: UNNotificationPresentationOptions) -> Void )

2. On Flutter side, this triggers a navigation.

3. In the screen the navigation is navigating:
   @override void initState() { super.initState(); unawaited(ScreenProtector.preventScreenshotOn()); }

Not going to post the stacktrace again, it's more or less the same. What is odd, there are no logs triggered either on Flutter or native side (spammed the userNotificationCenter with NSlog) before the memory access error.

I'll try to make a minimal reproducible example, but it may take a while.

[prongbang]

Thanks for the update, tried the 1.4.5 version but unfortunately it did not fix the crash on iOS 15.8.5 so we keep using v1.4.3 for now.

Our case when the crash happens:

1. We call a flutter message channel method in AppDelegate.swift (FlutterBasicMessageChannel generated by pigeon) when apns push arrives in the foreground:
   override func userNotificationCenter( _ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (_ options: UNNotificationPresentationOptions) -> Void )
2. On Flutter side, this triggers a navigation.
3. In the screen the navigation is navigating:
   @override void initState() { super.initState(); unawaited(ScreenProtector.preventScreenshotOn()); }

Not going to post the stacktrace again, it's more or less the same. What is odd, there are no logs triggered either on Flutter or native side (spammed the userNotificationCenter with NSlog) before the memory access error.

I'll try to make a minimal reproducible example, but it may take a while.

I suspect that the unawaited call may execute too early, possibly before the view has been fully loaded or attached to the window.

Have you tried these solutions to see if the crash still occurs?

Solution 1

@override
void initState() {
  super.initState();
  WidgetsBinding.instance.addPostFrameCallback((_) {
    unawaited(ScreenProtector.preventScreenshotOn());
  });
}

Solution 2

@override
void initState() {
  super.initState();
  _preventScreenshotOn();
}

void _preventScreenshotOn() async {
  await ScreenProtector.preventScreenshotOn();
}

Do you still encounter the crash after trying either of these approaches?

[qeepcologne]

i cannot reproduce it, but i can say, that there are lots of crashes (EXC_BAD_ACCESS KERN_PROTECTION_FAILURE) still with version 1.4.5 on ios 15,18 & 26.

[sAw-hTet-nAing]

I'm experiencing the same issue on iOS. In my case, the app crashes whenever there is a BannerAd widget from the google_mobile_ads package displayed.

Environment
Plugin version: 1.4.5 (first noticed)
Flutter SDK:

Flutter 3.38.0-1.0.pre-498 • channel master • https://github.com/flutter/flutter.git
Framework • revision ab919febb3 (29 hours ago) • 2025-11-11 05:43:23 +0700
Engine • hash a193414ca397f83d08032e4b0bba82b62626153b (revision aa9dc9ac54) (27 hours ago) • 2025-11-10 21:26:18.000Z
Tools • Dart 3.11.0 (build 3.11.0-114.0.dev) • DevTools 2.52.0

Platform: iOS

Steps to Reproduce
Add a BannerAd widget from google_mobile_ads.
Run the app on an iOS device or simulator.
Observe that the app crashes after the ad loads or renders.

Additional Information
The crash only happens on iOS (works fine on Android).
The issue appeared right after updating the Flutter SDK.