MediaPlayerControl Decode Exception in v12

[begleysm]

I'm working on upgrading my App to from 11.3.11 to 12.0.1. I seem to have almost everything updates/work except...

I rely heavily on the MediaPlayerControl and it now crashes at runtime with a

System.InvalidOperationException: Unknown error oocured: Decode
   at Avalonia.Controls.MediaPlayerControl.s(Object a, MediaPlayerErrorEventArgs b)

exception any time I try to actually play media on Windows.

On Android I get similar behavior that when the media tries to play I get

2026-04-22 21:22:52.752 30117-30352 ExoPlayerImplInternal   com.xxxxxxxxxx.yyyyyy                E  Playback error
androidx.media3.exoplayer.ExoPlaybackException: Source error
at androidx.media3.exoplayer.ExoPlayerImplInternal.handleIoException(ExoPlayerImplInternal.java:864)
...
Caused by: androidx.media3.datasource.FileDataSource$FileDataSourceException: java.io.FileNotFoundException: /data/user/0/com.xxxxxxxxxx.yyyyyy/files/temp_2902403c-ac5f-4c77-ae6c-36d384d97e4c.tmp: open failed: ENOENT (No such file or directory)
at androidx.media3.datasource.FileDataSource.openLocalFile(FileDataSource.java:203)
...
Caused by: java.io.FileNotFoundException: /data/user/0/com.xxxxxxxxxx.yyyyyy/files/temp_2902403c-ac5f-4c77-ae6c-36d384d97e4c.tmp: open failed: ENOENT (No such file or directory)
at libcore.io.IoBridge.open(IoBridge.java:574)
... 
Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
at libcore.io.Linux.open(Native Method)
...

I've read over (and applied the relevant) Breaking Changes recommendations. I've worked with AI a bit to try to debug. I've tried MediaSource = StreamSource and MediaSource = UriSource. Again, this all worked in 11.3.11.

Any ideas on what I might need to do to get media playing again?