[Bug] MSAL causes hangs in UWP app

[tipa]

In the Microsoft Partner Center I see "failures" reported as hangs for my Store-published app that seem to originate from MSAL:

0	.	HANG_QUIESCE	0x0000000000000000
1	unknown.dll	[.ecxr]	0x0000000000000000
2	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::Linq::JObject.Load	0x0000000000000000
3	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::Linq::JObject.Parse	0x0000000000000000
4	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Cache::Items::CacheSerializationContract.FromJsonString	0x0000000000000000
5	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Cache::TokenCacheJsonSerializer.Deserialize	0x0000000000000000
6	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::TokenCache.Microsoft.Identity.Client.ITokenCacheSerializer.DeserializeMsalV3	0x0000000000000000
7	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Platforms::uap::SynchronizedAndEncryptedFileProvider::_OnBeforeAccessAsync_d__6.MoveNext	0x0000000000000000
8	SharedLibrary.dll	System::Runtime::CompilerServices::AsyncMethodBuilderCore::MoveNextRunner::__c._CallMoveNext_b__3_0	0x0000000000000000
...
23	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Platforms::uap::SynchronizedAndEncryptedFileProvider::_ReadAndDecryptAsync_d__9.MoveNext	0x0000000000000000

0	.	HANG_QUIESCE	0x0000000000000000
1	unknown.dll	[.ecxr]	0x0000000000000000
2	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::JsonReader.SetToken	0x0000000000000000
3	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::JsonTextReader.ParseValue	0x0000000000000000
4	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::JsonTextReader.Read	0x0000000000000000
5	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::Linq::JObject.Load	0x0000000000000000
6	Microsoft.Identity.Client.dll	Microsoft::Identity::Json::Linq::JObject.Parse	0x0000000000000000
7	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Cache::Items::CacheSerializationContract.FromJsonString	0x0000000000000000
8	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Cache::TokenCacheJsonSerializer.Deserialize	0x0000000000000000
9	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::TokenCache.Microsoft.Identity.Client.ITokenCacheSerializer.DeserializeMsalV3	0x0000000000000000
10	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Platforms::uap::SynchronizedAndEncryptedFileProvider::_OnBeforeAccessAsync_d__6.MoveNext	0x0000000000000000
...
26	Microsoft.Identity.Client.dll	Microsoft::Identity::Client::Platforms::uap::SynchronizedAndEncryptedFileProvider::_ReadAndDecryptAsync_d__9.MoveNext	0x0000000000000000

Not sure if that's relevant but the device this hang was reported from runs Windows 10.0.22621

Which version of MSAL.NET are you using? 4.44.0

Platform UWP, interactive auth flow

[bgavrilMS]

The stack trace seems to indicate a JSON deserialization failure that has to do with the cache. Is it possible to capture an error message or have any way to repro this?

[tipa]

I am not able to reproduce it and I don't know how Windows collects that information (or event determines when a hang is a hang). I don't even know if the user would have noticed something or if the method just was very slow. I was just surprised that working with JSON would cause a hang and I have found no indication that working with JSON in other parts of my apps would cause a hang

[bgavrilMS]

If cache serialization fails, MSAL will continue without it, storing the tokens in memory only. App should not be impacted. But when user restarts the app, they might have to re-login.

[bgavrilMS]

We are upgrading MSAL's UWP reference and internal JSON serialization in 4.45 (out soon). Would be intereseting to see if the problems continue to occur.

[bgavrilMS]

Won''t fix. Please upgrade to WinUI.