Element iOS App 1.11.9 crashes or hangs on downloading 85mb mp4 video.

[LutzLange]

Steps to reproduce

Using ESS 24.04.03 airgapped with Element iOS 1.11.9 connected through VPN and Proxy.

Downloading an 85mb mp4 video with 8 devices at the same time results in :

4 successful downloads
2 crashed apps
2 hung apps

Outcome

What did you expect?

The downloads should have worked on all devices.

What happened instead?

2 hung apps
2 crashed apps on iPhone 13 with iOS 17.* and iPad Pro 17.4.1

Your phone model

iphone 13 and iPad Pro

Operating system version

17.X

Application version

1.11.9

Homeserver

ESS 24.04.03

Will you send logs?

Yes

[LutzLange]

We will run the test again and upload rage + link rage shakes.

[LutzLange]

They tested again today 4pm German time.

Their apps crashed again now all but one.

They tell me that they did create Rage Shakes with the String "Video Test Brandenburg"

[LutzLange]

e.g. https://github.com/matrix-org/element-ios-rageshakes/issues/29600

[LutzLange]

Rage Shake is not activated for us. However, every time the app crashed, we clicked on User settings > Report error. Crashed several times today for everyone.

The problem also occurred several times where the sound continues to play after the video has ended. I also got a few new errors when trying to clear the cache and then even once when trying to report the error. Or sometimes it plays a video but still shows the loading icon at the same time. And here's something funny: if you press the play button several times in a video, it gets brighter and brighter until it's solid white.

We have entered ‘Video Test Brandenburg’ as the description for each error.

Download was not possible:

[pixlwave]

A quick look through the logs of the previous run (console.1.log) shows the devices are having connection issues (which doesn't explain the crashes):

The network connection was interrupted:

[MXMediaLoader] Failed to download media (https://matrix.home.server/_matrix/media/r0/download/home.server/zyfMmLOqxYxxplUqwhecDzWY): Error Domain=NSURLErrorDomain Code=-1005 "Die Netzwerkverbindung wurde unterbrochen." UserInfo={NSUnderlyingError=0x3022ac0c0 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "Die Netzwerkverbindung wurde unterbrochen." UserInfo={NSErrorFailingURLStringKey=https://matrix.home.server/_matrix/media/r0/download/home.server/zyfMmLOqxYxxplUqwhecDzWY, NSErrorFailingURLKey=https://matrix.home.server/_matrix/media/r0/download/home.server/zyfMmLOqxYxxplUqwhecDzWY, NSErrorPeerAddressKey=<CFData 0x300e09c20 [0x1fb413eb0]>{length = 16, capacity = 16, bytes = 0x100201bb000000000000000000000000}, NSLocalizedDescription=Die Netzwerkverbindung wurde unterbrochen.}}, NSErrorFailingURLStringKey=https://matrix.home.server/_matrix/media/r0/download/home.server/zyfMmLOqxYxxplUqwhecDzWY, NSErrorFailingURLKey=https://matrix.home.server/_matrix/media/r0/download/home.server/zyfMmLOqxYxxplUqwhecDzWY, NSLocalizedDescription=Die Netzwerkverbindung wurde unterbrochen.}

and

Request timed out:

[MXMediaLoader] Failed to download media (https://matrix.home.server/_matrix/media/r0/download/home.server/YtUyFrGndGNODRQwgoMlLlKK): Error Domain=NSURLErrorDomain Code=-1001 "Zeitüberschreitung bei der Anforderung." UserInfo={NSUnderlyingError=0x3032bc660 {Error Domain=kCFErrorDomainCFNetwork Code=-1001 "Zeitüberschreitung bei der Anforderung." UserInfo={NSErrorFailingURLStringKey=https://matrix.home.server/_matrix/media/r0/download/home.server/YtUyFrGndGNODRQwgoMlLlKK, NSErrorFailingURLKey=https://matrix.home.server/_matrix/media/r0/download/home.server/YtUyFrGndGNODRQwgoMlLlKK, _kCFStreamErrorCodeKey=-2102, _kCFStreamErrorDomainKey=4, NSLocalizedDescription=Zeitüberschreitung bei der Anforderung.}}, NSErrorFailingURLStringKey=https://matrix.home.server/_matrix/media/r0/download/home.server/YtUyFrGndGNODRQwgoMlLlKK, NSErrorFailingURLKey=https://matrix.home.server/_matrix/media/r0/download/home.server/YtUyFrGndGNODRQwgoMlLlKK, _kCFStreamErrorDomainKey=4, _kCFStreamErrorCodeKey=-2102, NSLocalizedDescription=Zeitüberschreitung bei der Anforderung.}

[LutzLange]

The errors will only pop up for the mobile devices which are connected through a VPN + Proxy connection to the synapse server. The security team at the customer is insisting on inspecting all traffic. My current guess is that their Proxy can't cope with the load that they put onto the proxy system which is a cheap RHEL and not a powerful hardware box.

[LutzLange]

The iOS App is not dealing well with these errors is my guess. They report strange errors playing this MP4 video. Will the playback start before the file is fully fetched? Or how does it work?

[LutzLange]

They retested and were able to increase network throughput. But the behavior of the iOS Element App on reaching the network capacity limit remains the same.

We need a graceful reaction to Network issues on downloading attachments! Crash or Hangs of the App are not acceptable.

[pixlwave]

Fixed by #7799, the cause was launching tapping the play button multiple times which the upset the app handling all the failures.