Bug PersistentManager.ReadAndActivateObjectThreaded crash (Android and iOS)

We observe a lot of crashes like this for both Android and iOS:

Code (CSharp):

1. Crashed: Loading.PreloadManager
2. 0  UnityFramework                 0x100e4e07c PersistentManager::ReadAndActivateObjectThreaded(int, SerializedObjectIdentifier const&, SerializedFile*, bool, bool, PersistentManager::LockFlags) + 2693812
3. 1  UnityFramework                 0x100e4e29c PersistentManager::LoadObjectsThreaded(int const*, int, LoadProgress&, bool, PersistentManager::LockFlags) + 2694356
4. 2  UnityFramework                 0x100d51cd4 LoadOperation::Perform() + 1660684
5. 3  UnityFramework                 0x100a67edc AssetBundleLoadAssetOperation::Perform() + 1710792
6. 4  UnityFramework                 0x100d543c0 PreloadManager::ProcessSingleOperation() + 1670648
7. 5  UnityFramework                 0x100d54164 PreloadManager::Run() + 1670044
8. 6  UnityFramework                 0x100d540d0 PreloadManager::Run(void*) + 1669896
9. 7  UnityFramework                 0x100dbca08 Thread::RunThreadWrapper(void*) + 2098240
10. 8  libsystem_pthread.dylib        0x21eae92c0 _pthread_body + 128
11. 9  libsystem_pthread.dylib        0x21eae9220 _pthread_start + 44
12. 10 libsystem_pthread.dylib        0x21eaeccdc thread_start + 4

We use Unity 2019.4.21 and adressables to load content.

Does anyone experience similar problems? Is there a workaround?

 

It's been a month an no reply yet. We have this issue for ~1% of active users. We're sure it's not a memory issue as there are crash reports with more 1Gb of free RAM.

 

I can confirm it does happen. After upgrading from 2017 to 2019 we started to get this bug reported in ~1% of users. Actually it sometimes have different stacktrace but it is happening on disposing
UnityWebRequestAssetBundle.GetAssetBundle(url, crc) request or one frame after successful download of assetbundle. We have debug logs after download and right before dispose. On android most errors happens after dispose log. On ios most errors happens on successful download log before calling dispose.

Edit: Looking at our logs we see this happening only on asset bundles containing scenes.

 

bump

 

We're also seeing this on 2018.4.30f1

 

Can we get a response from Unity devs on this? @Ryanc_unity

 

We are seeing the same problem.

 

For everyone interested, here's a link to the issue on bugtracker: https://issuetracker.unity3d.com/issues/mobile-high-crash-rates-in-loading-dot-preloadmanager. They claim to fix it in 2019/2020 LTS. After some testing I can say, that crash rates went down, but we still observe the issue in crashlytics.

 

We're seeing similar crashes on 2021.2.17 with addressable 1.19.19 version. In our case, crashes seem to appear after upgrading from 2020.3.18 to 2021.2.17.