[BUG] Player crashes on change of language

[sarthaksingh100]

The player crashes or shows error as soon as i change the language of the playing video. Apart fromt this the default audio selection is not working properly.

[ProdigyV21]

Fixed and will ship in v1.9.8.

What was wrong

Two code paths in PlayerScreen.kt (the D-pad handler and the onSelectAudio callback) built a TrackSelectionOverride(group, trackIndex) after validating groupIndex < trackGroups.size but not trackIndex < group.length. There was also no try/catch around the operation.

Root cause: AudioTrackInfo captures groupIndex / trackIndex at the moment onTracksChanged fires. Between that moment and the user actually picking a track from the menu (several seconds later, especially if they opened the subtitle menu first), the player may have re-prepared due to adaptive stream switch, source reselection, external subtitle MediaItem rebuild, or transient-error recovery. After any of those events the cached trackIndex could be out of bounds for the new group layout, and Media3's TrackSelectionOverride constructor throws IllegalArgumentException — crashing the player.

The fix

Landed in #129 (merged to main). Extracted the audio-track selection logic into a single private helper applyAudioTrackSelection(exoPlayer, track, audioTracks) that:

• Wraps the whole operation in try/catch for IllegalArgumentException, IllegalStateException, and generic exceptions.
• Calls clearOverridesOfType(C.TRACK_TYPE_AUDIO) before setting the new override so stale overrides from prior selections can't pin the player to a no-longer-present track.
• Validates groupIndex in groups.indices, group.type == TRACK_TYPE_AUDIO, AND trackIndex in 0 until group.length before calling TrackSelectionOverride(...) — this is the specific check that was missing.
• Falls back to setPreferredAudioLanguage alone if validation fails, so Media3 picks the closest matching track on its own rather than leaving you on the wrong language.
• Returns Int? so the caller keeps the previous selection on failure instead of jumping to an incorrect one.

Testing

Please verify on v1.9.8:

1. Play a movie or episode with multiple audio tracks.
2. Open the audio track menu mid-playback.
3. Switch to a different language.
4. Do it multiple times, including after pausing, after the player prepares a new source, and after switching subtitle tracks.
5. Verify no crash.

If the player still crashes when switching audio language on 1.9.8, please open a new issue with:

• The content being played
• Which language you were switching from and to
• adb logcat output from around the crash (adb logcat *:E)
• Whether you had just done something else before (source switch, subtitle change, pause/resume)

Closing as resolved.