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