Sporadic crashes in AnimationMixer

[brane-games]

Tested versions

• Reproducible in v4.2.1 and v4.2.2

System information

Windows 10 / Vulkan API 1.3.242 - Forward+ - Using Vulkan Device #0: NVIDIA - NVIDIA GeForce GTX 1660

Issue description

Lately my game has been crashing more often, so I've built a custom build with debug symbols in order to get to the bottom of it.
This crash happens only occasionally, and logs nothing in the normal build of the engine.

Can anyone help me with understanding what the problem is and how could I go around it? Would just not using AnimationPlayer anywhere be good enough?

Here's the backtrace:

================================================================
CrashHandlerException: Program crashed
Engine version: Godot Engine v4.2.1.stable.mono.custom_build (b09f793f564a6c95dc76acc654b390e68441bd01)
Dumping the backtrace. Please include this when reporting the bug to the project developer.
[0] Object::set (C:\godot\core\object\object.cpp:230)
[1] Object::set (C:\godot\core\object\object.cpp:230)
[2] Object::set_indexed (C:\godot\core\object\object.cpp:408)
[3] AnimationMixer::_blend_process (C:\godot\scene\animation\animation_mixer.cpp:1447)
[4] AnimationMixer::_process_animation (C:\godot\scene\animation\animation_mixer.cpp:940)
[5] AnimationMixer::_notification (C:\godot\scene\animation\animation_mixer.cpp:2046)
[6] AnimationMixer::_notificationv (C:\godot\scene\animation\animation_mixer.h:44)
[7] AnimationPlayer::_notificationv (C:\godot\scene\animation\animation_player.h:39)
[8] Object::notification (C:\godot\core\object\object.cpp:840)
[9] SceneTree::_process_group (C:\godot\scene\main\scene_tree.cpp:950)
[10] SceneTree::_process (C:\godot\scene\main\scene_tree.cpp:1023)
[11] SceneTree::process (C:\godot\scene\main\scene_tree.cpp:510)
[12] Main::iteration (C:\godot\main\main.cpp:3634)
[13] OS_Windows::run (C:\godot\platform\windows\os_windows.cpp:1474)
[14] widechar_main (C:\godot\platform\windows\godot_windows.cpp:182)
[15] _main (C:\godot\platform\windows\godot_windows.cpp:206)
[16] main (C:\godot\platform\windows\godot_windows.cpp:218)
[17] __scrt_common_main_seh (D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288)
[18] <couldn't map PC to fn name>
-- END OF BACKTRACE --
================================================================

Steps to reproduce

The best I can do is provide the backtrace. In the code that crashes:

• my game data is laoded
• the main scene of the game is instantiated
• the current Start menu scene is removed

Minimal reproduction project (MRP)

This one isn't possible to provide as it's my whole commercial project that suffers from this.

[TokageItLab]

Should have been already fixed in 4.3 by #86687.

[brane-games]

Can confirm it's not happening ever since I tried 4.3! Thanks @TokageItLab !