iOS: Crashed: BackgroundWorker > DownloadHandlerAssetBundle::Prepare()

We're getting this crash report on many devices mostly iPhone
Crashed: BackgroundWorker
DownloadHandlerAssetBundle.Prepare() (DownloadHandlerAssetBundle.cpp:197)
UnityWebRequestProto<TransportiPhone, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, HeaderHelper, AsyncOperation>.Prepare() (WebRequestProto.h:387)

Spoiler: Crash Details

0x10191dcc8 DownloadHandlerAssetBundle.Prepare() (DownloadHandlerAssetBundle.cpp:197)

0x101920d1c UnityWebRequestProto<TransportiPhone, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, HeaderHelper, AsyncOperation>.Prepare() (WebRequestProto.h:387)

0x101920204 UnityWebRequestProto<TransportiPhone, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, HeaderHelper, AsyncOperation>.Task_PrepareRequest(void*) (WebRequestProto.h:115)

0x101920254 UnityWebRequestProto<TransportiPhone, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, HeaderHelper, AsyncOperation>.Job_ExecuteUnityWebRequest(UnityWebRequestProto<TransportiPhone, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, HeaderHelper, AsyncOperation>*) (dynamic_array.h:381)

0x101708b4c JobQueue.Exec(JobInfo*, long long, int) (JobQueue.cpp:353)

0x101708ab8 JobQueue.Steal(JobGroup*, JobInfo*, long long, int, bool) (JobQueue.cpp:559)

0x101708e90 JobQueue.ExecuteJobFromQueue() (JobQueue.cpp:716)

0x101708f38 JobQueue.ProcessJobs(void*) (JobQueue.cpp:765)

0x1017085c0 JobQueue.WorkLoop(void*) (JobQueue.cpp:852)

0x1018c5160 Thread.RunThreadWrapper(void*) (Thread.cpp:35)

0x184d5c2b4 _pthread_body + 308

0x184d5c180 _pthread_body + 310

0x184d5ab74 thread_start + 4

We are using Unity 2017.1.2p4 and Xcode 9.1

 

It happened with me using Unity 2017.1.2p4,
any updates?

 

Please let me know if you need more details about the issue

 

I'm also seeing issues on iOS with BackgroundWorker > UnityWebRequestProto.h:207

It's not exactly the same stack, but may be related since it seems to have started happening recently?

Unity 2017.3.0f2, running on iPhone 6S, ios version 11.2.1

The first time my app runs (after uninstall) it seems fine, on subsequent runs it often freezes while doing some HTTPS requests (among other things). Maybe points to a problem with the cache?

Spoiler: Stack-crashed-thread

* thread #21, name = 'BackgroundWorker', stop reason = EXC_BAD_ACCESS (code=257, address=0x41) frame #0: 0x0000000000000041 * frame #1: 0x000000010561f718 horizonexplorer`::Job_ExecuteUnityWebRequest() at UnityWebRequestProto.h:207 [opt] frame #2: 0x000000010533fb08 horizonexplorer`::Exec() [inlined] ExecuteJobFunc at JobQueue.cpp:386 [opt] frame #3: 0x000000010533faf4 horizonexplorer`::Exec() at JobQueue.cpp:440 [opt] frame #4: 0x000000010533fa74 horizonexplorer`::Steal() at JobQueue.cpp:573 [opt] frame #5: 0x000000010533fe4c horizonexplorer`::ExecuteJobFromQueue() at JobQueue.cpp:770 [opt] frame #6: 0x000000010533fef8 horizonexplorer`:rocessJobs() at JobQueue.cpp:823 [opt] frame #7: 0x000000010533f57c horizonexplorer`::WorkLoop() at JobQueue.cpp:893 [opt] frame #8: 0x00000001053aef1c horizonexplorer`::RunThreadWrapper() at Thread.cpp:36 [opt] frame #9: 0x0000000180ea02b4 libsystem_pthread.dylib`_pthread_body + 308 frame #10: 0x0000000180ea0180 libsystem_pthread.dylib`_pthread_start + 312 frame #11: 0x0000000180e9eb74 libsystem_pthread.dylib`thread_start + 4

 

i am having similar issues with unity 2017.3.0f3
happens when sending logs with unitywebrequests

 

Here are some logs of my crash, running 2017.3.0f3 on an iOS device (ipad)

assembly:
0x105476e18 <+60>: blr x8
-> 0x105476e1c <+64>: ldr x8, [x19, #0xe0] . BackgroundWorker (32): EXC_BAD_ACCESS (code=257, address=0x41)
0x105476e20 <+68>: cbnz x8, 0x105476e00 ; <+36> [inlined] back + 4 at UnityWebRequestProto.h:204
0x105476e24 <+72>: add x0, sp, #0x8 ; =0x8
0x105476e28 <+76>: bl 0x104eca988 ; ::~AutoLock() at Mutex.h:30
0x105476e2c <+80>: mov x0, x19
0x105476e30 <+84>: bl 0x1054776d0 ; ::Release() at UnityWebRequestProto.h:353
0x105476e34 <+88>: b 0x105476e40 ; <+100> at UnityWebRequestProto.h:219
0x105476e38 <+92>: add x0, sp, #0x8 ; =0x8
0x105476e3c <+96>: bl 0x104eca988 ; ::~AutoLock() at Mutex.h:30

output window:
2017-12-31 23:31:24.970507+0200 vixeo[5668:3311942] TIC TCP Conn Failed [34:0x1c4574340]: 1:50 Err(50)

2017-12-31 23:31:24.971885+0200 vixeo[5668:3311942] Task <5731C406-9933-417A-B2CA-B2F8940CDCE0>.<0> HTTP load failed (error code: -1009 [1:50])

2017-12-31 23:31:24.972079+0200 vixeo[5668:3312120] NSURLConnection finished with error - code -1009

 

I am having the same problem on the same device and OS version, is there an eta for a fix?

 

With 2017.1.2p4, All of Editor, Android and iOS crash when calling UnityWebRequest.Abort() or UnityWebRequest.Dispose() while downloading data.

 

You're right. Only assetbundles. Do you know when this issue will be resolved?

 

Still crashed on 2017.1.3p1 (Android):

Is there issue ticket for tracking this issue?

 

I have a similar issue. After i updated to 2017.3.0p4, my app started crashing every time i try to download an assetbundle without internet connection. Works fine in 2017.2

 

I am facing same problem with web request in version 2017.3.1f. Is there any way to resolve this issue?

 

@

Any updates?

 

We are suffering from this as well. In our case it's when using the Amazon SDK for Unity to download files from S3 on iPhone. We are using Unity 2017.3.1p3.

EXC_BAD_ACCESS (code=1, address=0xffffffff00000000)

Code (asm):

1. 0x00000001025413b4 in ::Job_ExecuteUnityWebRequest() at /Users/builduser/buildslave/unity/build/Modules/UnityWebRequest/Public/Prototypes/UnityWebRequestProto.h:207
2. 0x000000010207c854 in ExecuteJobFunc [inlined] at /Users/builduser/buildslave/unity/build/Runtime/Jobs/Internal/JobQueue.cpp:386
3. 0x000000010207c840 in ::Exec() at /Users/builduser/buildslave/unity/build/Runtime/Jobs/Internal/JobQueue.cpp:440
4. 0x000000010207c7c0 in ::Steal() at /Users/builduser/buildslave/unity/build/Runtime/Jobs/Internal/JobQueue.cpp:573
5. 0x000000010207cb98 in ::ExecuteJobFromQueue() at /Users/builduser/buildslave/unity/build/Runtime/Jobs/Internal/JobQueue.cpp:770
6. 0x000000010207cc78 in ::ProcessJobs() at /Users/builduser/buildslave/unity/build/Runtime/Jobs/Internal/JobQueue.cpp:823
7. 0x000000010207c298 in ::WorkLoop() at /Users/builduser/buildslave/unity/build/Runtime/Jobs/Internal/JobQueue.cpp:893
8. 0x0000000102152d50 in ::RunThreadWrapper() at /Users/builduser/buildslave/unity/build/Runtime/Threads/Thread.cpp:36
9. 0x000000019028575c in _pthread_body ()
10. 0x000000019028566c in _pthread_start ()
11. 0x0000000190282d84 in thread_start ()

 

We have this same crash, as Adam posted above. Are you using the AWS SDK? (I'm hoping not, would be nice to narrow it down...)

Repro'd on:
2017.3.0f3, 2017.3.1f1, 2017.3.1p3
2018.1.0b9

NO repro on:
2017.2.1p4, 2017.2.2f1

We're going to try and ship with 2017.2.2f1... fingers crossed.

 

I tried to vote but ain't letting me do it: "Voting disabled for resolved issues (Fixed)"

At the top of the page there's a banner that reads "Fixed in future release"

What's the status of this after all? If fixed in a future release, which release is that one? Any workaround in the meantime?

 

@Aurimas-Cernius, does the fix you mention apply to all of the

UnityWebRequestProto

-related call stacks reported in this thread or just some of them? (And I realize the fix hasn't been released yet.)

For what it's worth, I just reproduced my crash in Unity 2018.1.0b12 and I have a slightly more verbose call stack than my earlier report. Again, this is on iPhone with IL2CPP.

Crashed: BackgroundWorker
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000000

Code (asm):

1. 0x1027345f4 UnityWebRequestProto<UnityWebRequestTransport, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, CertificateHandler, HeaderHelper, AsyncOperation>::Job_ExecuteUnityWebRequest(UnityWebRequestProto<UnityWebRequestTransport, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, CertificateHandler, HeaderHelper, AsyncOperation>*) (dynamic_array.h:471)
2. 0x1021bc560 JobQueue::Exec(JobInfo*, long long, int) (JobQueue.cpp:413)
3. 0x1021bc4a4 JobQueue::Steal(JobGroup*, JobInfo*, long long, int, bool) (JobQueue.cpp:657)
4. 0x1021bc8dc JobQueue::ExecuteJobFromQueue() (JobQueue.cpp:814)
5. 0x1021bc9a8 JobQueue::ProcessJobs(void*) (JobQueue.cpp:867)
6. 0x1021bbf7c JobQueue::WorkLoop(void*) (JobQueue.cpp:953)
7. 0x1022c71a8 Thread::RunThreadWrapper(void*) (Thread.cpp:36)
8. 0x18b48175c _pthread_body + 240
9. 0x18b48166c _pthread_body + 282
10. 0x18b47ed84 thread_start + 4

 

Hello. I have the same issue on iOS, but it doesn't refer to AssetBundles.
Here is my code:

Code (CSharp):

1.  
2. public UnityWebRequest Load(string uri, Dictionary<string, string> headers, System.Action<DownloadHandler> onSuccessAction, System.Action<string> onFailAction) {
3.     UnityWebRequest unityWebRequest = UnityWebRequest.Get(uri);
4.     StartCoroutine(LoadCoroutine(unityWebRequest, onSuccessAction, onFailAction));
5.     return unityWebRequest;
6.   }
7.  
8.   private IEnumerator LoadCoroutine(UnityWebRequest unityWebRequest, System.Action<DownloadHandler> onSuccessAction, System.Action<string> onFailAction) {
9.  
10.     yield return unityWebRequest.SendWebRequest();
11.  
12.     if (unityWebRequest.isNetworkError) {
13.       onFailAction(unityWebRequest.error);
14.       yield break;
15.     }
16.     onSuccessAction(unityWebRequest.downloadHandler);
17.     unityWebRequest.downloadHandler.Dispose();
18.   }

And when I send a request it returns UnknownError in unityWebRequest.error for the first time and my application crashes when I try to send it again. Here is an XCode log with error BackgroundWorker (24): EXC_BAD_ACCESS (code=257, address=0x41):

Code (asm):

1. 0x1039ce588 <+52>:  cbz    x8, 0x1039ce5b0           ; <+92> [inlined] ~AutoLock at UnityWebRequestProto.h:216
2.     0x1039ce58c <+56>:  mov    x0, x19
3.     0x1039ce590 <+60>:  blr    x8
4. ->  0x1039ce594 <+64>:  ldr    x8, [x19, #0xe0]
5.     0x1039ce598 <+68>:  cbnz   x8, 0x1039ce578           ; <+36> [inlined] back + 4 at UnityWebRequestProto.h:204
6.     0x1039ce59c <+72>:  add    x0, sp, #0x8              ; =0x8
7.     0x1039ce5a0 <+76>:  bl     0x10363c1e4               ; ::~AutoLock() at Mutex.h:30
8.     0x1039ce5a4 <+80>:  mov    x0, x19
9.     0x1039ce5a8 <+84>:  bl     0x1039cee48               ; ::Release() at UnityWebRequestProto.h:353
10.     0x1039ce5ac <+88>:  b      0x1039ce5b8               ; <+100> at UnityWebRequestProto.h:219

So, how can I fix it right now? I can't wait an update and my app uses Vuforia 7 functionality, that allowed only for 2017.3 and later versions. Furthermore, downgrading to 2017.2.2f1 crashes all asset references in my scene.

 

@Averge, are you able to distill your crash down to a minimal repro case that you can submit to Unity? Your crash looks identical to mine. I've been trying to create a minimal repro case but I haven't been successful yet. I'm still trying though.

 

@Averge , the way we successfully worked around this issue was to check for the responseCode right after calling SendWebRequest(). If 0, we assume the network is inaccessible and we set a time threshold (we set it in 1 second). Thus, next time we are to call SendWebRequest() we first check whether we still are within the time threshold, in which case we skip the call. Must say that our app is offline-capable so skipping a web request ain't critical for the app to run. This may not be everyone's case. In our scenario, we stopped getting crashes this way. In summary:

Code (CSharp):

1. void MyFunctionThatIssuesAWebRequest()
2. {
3.    var myRequest = new UnityWebRequest(...);
4.    // request setup follows
5.    ...
6.  
7.    if (CrashPreventionThresholdIsOpen()) {
8.       yield break; // skip request or face the risk of a crash
9.    } else {
10.       yield return myRequest.SendWebRequest();
11.    }
12.  
13.    if (myRequest.responseCode == 0) {
14.       // set a crash prevention time threshold for upcoming requests
15.    }
16.  
17.    // Rest of response analysis follows
18.    ...
19. }

This is a rough approximation to the idea of our workaround. It's a bit more elaborated than this but would be hard to extract the essential of the approach if fully pasted.

 

Thanks for the reply. Just want to confirm that you meant the upcoming 2018.1 instead of last-year-released 2017.1, right?

 

I was finally able to get a repro in a tiny project. I submitted to Unity. @Aurimas-Cernius here is the link to the report: https://fogbugz.unity3d.com/default.asp?1020451_tjom5fclu25evsg2
Thanks!

 

Do we have an ETA on when a patch build for 2017.3 (and .2 and .1) will be available with the asset bundle fix (https://issuetracker.unity3d.com/is...ing-to-stop-downloads-and-begin-new-via-www)? We have a fast approaching deadline for a customer and we <think> it is that issue which is causing our problems - but given there's at least one other web request problem; having a patch build with the asset bundle variant fixed sooner rather than later would be good.

It's been a few weeks since 2017.3.1p4, so hopefully there's something in the pipe very soon.

 

@Aurimas-Cernius
Will be backported this issue to 2017.4.x? I found that 2017.4.1f1 still has this issue.

 

FYI, we installed a copy of the 2018.2.0a7 build (linked in the discussion here https://fogbugz.unity3d.com/default.asp?1020451_tjom5fclu25evsg2) as that is the version that the Asset Bundle bug is reported to be fixed in, so that we could test whether that fix sorted <our> problem - and are happy to report that our issue is resolved.
So now we're just waiting on the patch build of 2017.3.1 to have the fix!

 

Any update on when there's going to be a new patch build for 2017.3.1? We rather desperately need our iOS only game to be able to work on... iOS

 

I'd take a pre-release version of 2017.3.1 that has the fix in it at the moment, so I could at least give our client a build that works for longer than 1 boot per install!

 

same bug here Unity 2017.3.1p4

 

 + 0

JobQueue::Exec(JobInfo*, long long, int) + 120

JobQueue::Steal(JobGroup*, JobInfo*, long long, int, bool) + 272

JobQueue::ExecuteJobFromQueue() + 100

JobQueue::ProcessJobs(void*) + 76

JobQueue::WorkLoop(void*) + 12

Thread::RunThreadWrapper(void*) + 64

_pthread_body + 124

_pthread_start + 44

thread_start + 0

same problem here at Unity 2017 3.1p4.

 

Yep, I can confirm that the fix has been in 2017.4 since 5f1
https://issuetracker.unity3d.com/is...ywebrequest-at-unitywebrequestproto-dot-h-222

 

Thanks. Update works. It won't crash when I turn on Airplane Mode.

But today another crash happend.

0

???

0x00000001a838bb70 + 0

1

UnityWebRequestProto<UnityWebRequestTransport, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, CertificateHandler, HeaderHelper, AsyncOperation>::Job_ExecuteUnityWebRequest(UnityWebRequestProto<UnityWebRequestTransport, AtomicRefCounter, RedirectHelper, ResponseHelper, DownloadHandler, UploadHandler, CertificateHandler, HeaderHelper, AsyncOperation>*) +64

2

JobQueue::Exec(JobInfo*, long long, int) + 144

3

JobQueue::Steal(JobGroup*, JobInfo*, long long, int, bool) + 292

4

JobQueue::ExecuteJobFromQueue() + 100

5

JobQueue::ProcessJobs(void*) + 100

6

JobQueue::WorkLoop(void*) + 12

7

Thread::RunThreadWrapper(void*) + 64

8

libsystem_pthread.dylib

__pthread_body + 128

9

libsystem_pthread.dylib

_pthread_start + 48

This just happend only one time when our QA team run the latest Unity version. It seems much more stable then 2017 3.1p4.
So I'm wondering if this crash fixable? I can see Adam-VisualVocal post abt this but I don't see any solution. Any update?

 

I am still getting this crash in 2019.3.0f6 - same problem for years now - iOS completely unusable because it loads lots of files and randomly crashes in one of these web requests at a different point even after loading the exact same files. Completely reproducible

 

It is completely impractical for me to send you my project. This issue is a global file handling problem, after a while if you try to download enough files with any sort of UnityWebRequest.SendWebRequest() you get an EXC_BAD_ACCESS and the app crashes immediately (my project makes extensive use of asset bundles and other downloadable files mainly text). It is always on yield UnityWebRequest.SendWebRequest() after any UnityWebRequest is set up - asset bundles or basic files. I have spent the last two days trying to work round the problem including trying to roll back to an earlier version but I have not had any success. It definitely crashes randomly in the last two released version of unity

same issue here: https://issuetracker.unity3d.com/is...local-file-with-file-slash-slash-slash-prefix