Out of memory bug when saving scene with a navigation mesh

[ComicoX]

ERROR: set: Condition ' p_index < 0 || p_index >= size() ' is true.
At: ./core/dvector.h:488
In the console every time I try to save a scene that has a new navigation mesh

Godot version: 3.0.6

Windows 10 x64

Steps to reproduce:
Open the scene from the project then create a navigation mesh and save the scene

Minimal reproduction project:
Bug.zip

[ComicoX]

Tried on 3.1 and it's happening as well

[ComicoX]

Is nobody going to talk about this issue. That you can't generate complex navigation meshes?

[Zireael07]

@ComicoTeam: You reported a bug one day ago, the team has a lot of bug reports (not to mention they are now doing a cleanup of the issues list in preparation for 3.1)

[ComicoX]

@Zireael07 I know that they are busy with 3.1. but the bug is present in that version as well

[DevMagicLord]

A navigationMeshInstance is not enough, you need both navigation and navmeshInstance, and you need to parent them like that
Navigation -> NavigationMeshInstance -> Your meshes

I added them to your scene, and i could bake the navmesh and save the scene without any issues with Godot 3.1 alpha 1
https://github.com/DevMagicLord/Godot3/blob/master/bugs/navmesh31alpha1.jpg

Godot would need better docs.

Also note that navmesh in Godot will need to improve, it doesn't work with physics , it's not optimized , and lacks some things like agent nodes (how it's done in Unity)
#17885

This will be worked on for 3.2
https://github.com/godotengine/godot-roadmap/blob/master/ROADMAP.md

[ComicoX]

@DevMagicLord The issue is still happening
And I've saw that godot has some issues with amd gpu's

[reduz]

Navigation mesh is too complex, and there is no way to fix this issue without breaking backwards compatibility. I suggest you use a simpler mesh manually created for this.

Will rewrite how navigation code works eventually for 4.0, so kicking this forward

[Calinou]

This was most likely resolved by #34776, closing. See #17885 (comment) if you need a solution in Godot 3.2.