Godot Engine Troubleshooting

Until there is a public Godot wiki that can be edited by the community I'll use this here temporary wiki to collect hints, do and don't, caveats.

As time passes, they may get fixed. If so, please edit this page :)

Playing Sounds in AnimationPlayer

When working with a play track (playing a sound on a SamplePlayer by keyframe) make sure to use discreete mode instead of continuous, or your sound sample will be triggered every step of the animation.

If using self.set_linear_velocity(vel) on a Rigid Body in its _fixed_process(), this overrides other physical forces like gravity.
self.set_linear_velocity(vel) must be called in _fixed_process() right from the start when the script beginns running. If not, then physics seem to be suspended for that object and set_linear_velocity() shows no effect. So it can't have an if that tests negative when the script starts, for example. If you bump into that object with another object that you can control, then suddenly physics are working again and set_linear_velocity() shows an effect.

If you'd like to use PolgonPathFinder from code, this PolygonPathFinder-Demo-GD-Script should help you get started.

Maybe this helps you prevent a crash that makes no sense.