[amplify_auth_cognito] type 'FetchAuthSessionFetching' is not a subtype of type 'FetchAuthSessionSuccess' in type cast

[hayashikun]

Description

An error type 'FetchAuthSessionFetching' is not a subtype of type 'FetchAuthSessionSuccess' in type cast occurs after calling Amplify.Auth.fetchAuthSession().

This is the stacktrace reported to Sentry.

Categories

• Analytics
• API (REST)
• API (GraphQL)
• Auth
• Authenticator
• DataStore
• Notifications (Push)
• Storage

Steps to Reproduce

We have not been able to reproduce it, but it is occurring at our distribution environments.

Screenshots

No response

Platforms

• iOS
• Android
• Web
• macOS
• Windows
• Linux

Flutter Version

3.19.3

Amplify Flutter Version

1.7.0

Deployment Method

Custom Pipeline

Schema

No response

[Jordan-Nelson]

@hayashikun Thanks for taking the time to open the issue.

Amplify Auth uses a state machine internally to fetch/refresh the user's session. From the info provided, it seems that the state machine is expecting the state machine to eventually resolve to a success state (or throw and exception), but that is not happening. It is not immediately clear to me how this could occur. I have a few follow up questions to try narrow down the issue.

• Is the stack trace that you provided the full stack trace? Do you have any additional logs?
• Do you have any info as to what APIs are being called or what the end user is doing when this occurs?
• Do you use the fetchAuthSession() API in your application? If so, do you use the forceRefresh option?
• Do you use the federateToIdentityPool() API?
• I see you specified this is happening on Windows. Can you confirm Windows is the OS running on the end user's device where this is occurring? Do your users use any other platforms? If so, which platforms are they using and is the issue occurring on those platforms?

[Jordan-Nelson]

@hayashikun if you are still facing this issue can you please provide answers to the questions above? Thank you

[Jordan-Nelson]

@hayashikun - I am going to close this out since we have not heard back. If you are still facing this issue please take a look at the questions above. Thanks.