MovieWriter FFwriter unavailable. Trying to use pillow instead

I have created a bar chart race in Matplotlib and now I am trying to save it into a gif file. I have imported the relevant library:

import matplotlib.animation as animation
plt.rcParams['animation.ffmpeg_path'] = '‪C:\\Program Files\\FFmpeg\\bin\\ffmpeg.exe'
FFwriter = animation.FFMpegWriter()

Here is the code I used to create my animation:

fig, ax = plt.subplots(figsize=(15, 8))
animator = animation.FuncAnimation(fig, draw_barchart, frames=range(1999, 2015))
HTML(animator.to_jshtml()) 

However, when I searched for the writers, there are only two of them:

animation.writers.list()

enter image description here

I had already installed FFmpeg following a tutorial on Wikihow, and I am also able to run FFmpeg from the command line, so I don't understand why it is not showing up. When I try to save my animation into a gif, I get this error message: enter image description here

Would anybody be familiar with this error message, please? Thank you very much.