Unable to send events since 3.20.0 - Invalid envelope header, duplicate field `sent_at`

[JadeBanks]

Package

Sentry

.NET Flavor

Xamarin

.NET Version

Xamarin.Android SDK 12.3.3.3

OS

Android

SDK Version

3.20.0

Self-Hosted Sentry Version

No response

Steps to Reproduce

This works with 3.19.0 but no longer in 3.20.0.

Problem occurs on both Android and iOS. I haven't tested on any other platforms.

Init and send events as described in the Sentry docs.

Expected Result

Expect to see events on the Sentry website

Actual Result

  Error: Sentry rejected the envelope . Status code: BadRequest. Error detail: invalid event envelope. Error causes: invalid envelope header, duplicate field `sent_at` at line 1 column 110.
  Debug: Failed envelope '' has payload: {"sdk":{"name":"sentry.dotnet","version":"3.20.0"},"sent_at":"2022-07-26T16:19:43.929796\u002B00:00","sent_at":"2022-07-26T16:19:59.401494+00:00"} {"type":"client_report","length":308} {"timestamp":"2022-07-26T16:19:43.925254+00:00","discarded_events":[{"reason":"before_send","category":"error","quantity":1},{"reason":"network_error","category":"default","quantity":13},{"reason":"network_error","category":"error","quantity":1},{"reason":"network_error","category":"session","quantity":9}]

This #1690 PR seems to be the likely cause.

[mattjohnsonpint]

Thanks. I was just debugging another issue and found the same thing. Fix coming asap, with a 3.20.1 release.

[mattjohnsonpint]

FYI - it only occurs if you have set a cache directory path in the options, or are using an SDK integration that sets one by default.