Vapoursynth help

[sosime]

Hi! I've been using vapoursynth to help make gifs for a while, and for the longest time I have been unable to use 4k videos. I downloaded vapoursynth portable using this guide: https://hackmd.io/@nibreon/vapoursynth-book but unfortunately, the op is no longer active :/
The script used is:

import vapoursynth as vs
import havsfunc as haf
import resamplehq as rhq
import G41Fun as fun
import kagefunc as kage
import mvsfunc as mvs

core = vs.get_core()

#core.max_cache_size = 1000 #Use this command to limit the RAM usage (1000 is equivalent to 1GB of RAM)

video = core.lsmas.LWLibavSource(source=r'video_cut\cut.mk v')

#Trim returns a clip with only the frames between the arguments first and last, or a clip of length frames, starting at first. a = first frame, b = last frame
#video = core.std.Trim(video, a, b)

#Whatever you copied from the resizer goes here

video = core.fmtc.bitdepth(video, bits=8)
video.set_output()


When I try to use a 4k video, I get the following error message:

Failed to evaluate the script:
Python exception: lsmas: failed to construct index.

Traceback (most recent call last):
File "src\cython\vapoursynth.pyx", line 1946, in vapoursynth.vpy_evaluateScript
File "src\cython\vapoursynth.pyx", line 1947, in vapoursynth.vpy_evaluateScript
File "C:/Users/acexu/Desktop/VapourSynth32Portable/gifs/script.vpy", line 12, in
video = core.lsmas.LWLibavSource(source=r'video_cut\cut.mk v')
File "src\cython\vapoursynth.pyx", line 1852, in vapoursynth.Function.__call__
vapoursynth.Error: lsmas: failed to construct index.

I only run into this issue with 4k videos. I am able to process 2k and 1080p videos no problem. I only use vapoursynth in my gifmaking process, so I'm not really literate with anything outside of that. Any help would be really appreciated!

[Selur]

'video_cut\cut.mk v'

seems wrong for a file path
also I would recommend using a 64bit setup