This is not possible, you're doing something wrong.
Download this SF2 file and NO OTHER ONE because I'm absolutely sure this SF2 file is working fine, click on the link below:
https://github.com/wrightflyer/SF2_Soun ... plus13.sf2
For downloading it click on this icon on the right side of the page and NO OTHER ONE:
It may take some seconds before the download starts because the file is preloaded. Be patient.
Pay attention to the folder where this SF2 file is being downloaded. For instance, it's just an example, let's say you're downloading it to D:\Sounds
Now you go to the menu Tools -> Preferences (at the bottom set: Show Settings = ALL) -> Input/Codecs -> Audio Codecs -> FluidSynth
On the right panel you click on the Browse button
Then you navigate to the folder where you have saved the SF2 file, in our example D:\Sounds\8mbgm_plus13.sf2
You select the 8mbgm_plus13.sf2 file so that the full path D:\Sounds\8mbgm_plus13.sf2 appears in the SoundFont File field as you can see in the screenshot I've posted in my previous post
Then you click on the Save button at the bottom, don't miss this step!
And finally you completly close and exit VLC.
It
must work.
If needed ask a friend to read this thread and to help you because it must work and I believe I can't be more clear.