Error with videos/_2018/fourier.py

I recently came across Manim, and thanks to Grant Sanderson, who open-sourced this great animation engine for explanatory math videos. Right now, I'm trying to reproduce videos/_2018/fourier.py with the following error message, how can I fix it?

(manimGL) xw@xw-Alienware-17-R5:~/xw-projects/manim-videos$ manimgl _2018/fourier.py ManimGL v1.7.2 01: AddingPureFrequencies 02: ApplyFourierToFourier 03: AskAboutAlmostFouierName 04: AskAboutInverseFourier 05: BeforeGettingToTheFullMath 06: BoundsAtInfinity 07: BreakApartSum 08: BuildUpExpressionStepByStep 09: CloseWithAPuzzle 10: DrawFrequencyPlot 11: EulersFormulaViaGroupTheoryWrapper 12: FilterOutHighPitch 13: FourierEndScreen 14: FourierMachineScene 15: Introduction 16: MachineThatTreatsOneFrequencyDifferently 17: MixingUnmixingTODOStub 18: MoreToCover 19: NextVideoWrapper 20: OneSmallNote 21: OtherContexts 22: PauseAndPonder 23: PuzzleDescription 24: ScaleUpCenterOfMass 25: ShowCommutativeDiagram 26: ShowLinearity 27: ShowLowerFrequency 28: ShowUncertaintyPrinciple 29: SimpleCosineWrappingAroundCircle 30: SponsorScreenGrab 31: StudentsHorrifiedAtScene 32: SubscribeOrBinge 33: SummarizeFormula 34: SummarizeTheFullTransform 35: TODOInsertCosineWrappingAroundCircle 36: TODOInsertUnmixingSound 37: TODOStub 38: TakeAStepBack 39: Thumbnail 40: UnmixMixedPaint 41: WhyAreYouTellingUsThis 42: WrapCosineGraphAroundCircle 43: WriteComplexExponentialExpression 44: XCoordinateLabelTypoFix

Select which scene to render (by name or number): 15

Traceback (most recent call last): File "/home/xw/anaconda3/envs/manimGL/bin/manimgl", line 8, in sys.exit(main()) File "/home/xw/anaconda3/envs/manimGL/lib/python3.10/site-packages/manimlib/main.py", line 61, in main run_scenes() File "/home/xw/anaconda3/envs/manimGL/lib/python3.10/site-packages/manimlib/main.py", line 39, in run_scenes scene.run() File "/home/xw/anaconda3/envs/manimGL/lib/python3.10/site-packages/manimlib/scene/scene.py", line 153, in run self.setup() File "/home/xw/xw-projects/manim-videos/./custom/characters/pi_creature_scene.py", line 264, in setup super().setup() File "/home/xw/xw-projects/manim-videos/./custom/characters/pi_creature_scene.py", line 49, in setup self.pi_creatures = VGroup(*self.create_pi_creatures()) File "/home/xw/xw-projects/manim-videos/./custom/characters/pi_creature_scene.py", line 284, in create_pi_creatures self.teacher = Mortimer(color=self.teacher_color) File "/home/xw/xw-projects/manim-videos/./custom/characters/pi_creature.py", line 311, in init super().init(mode, color, flip_at_start=flip_at_start, **kwargs) File "/home/xw/xw-projects/manim-videos/./custom/characters/pi_creature.py", line 74, in init self.init_structure() File "/home/xw/xw-projects/manim-videos/./custom/characters/pi_creature.py", line 101, in init_structure original_irises=VGroup(parts[2], parts[6]), IndexError: list index out of range