I'm getting these errors:
iCCP: known incorrect sRGB profile.
Condition '!elem' is true. returned: 0
Condition '!texture' is true.
But Godot doesn't specify where they come from... I supposed this had something to do with the color spaces of the images, but either I still have some texture with a weird color space, or it's something else.
EDIT: this doesn't prevent the game from running.