Followed the link in Help to download FFmpeg but it just gave me a 403 error.
Followed another chain of links which led back to the same place.
Tried Github & downloaded a zip. Unzipped but no “Install” exe there, just the three - ffmpeg.exe, ffplay.exe & ffprobe.exe along with a lot of html files in a “doc” folder + a “presets” folder. Is that it? Is this the “library”? Should I run one of the above .exe? Or place the lot in another folder to point to from Audacity?
Even the YouTube video on the Support page gives me an “Error 153 - Video player configuration error”.
(I’ve been working for years with several other A/V tools from Adobe through DaVinci Resolve without these hangups.)
Windows 10.
Which link? I don’t see a link in “Help”…
This one works. What you have to do when using Windows is out of my range, however.
And when a linked video does not play, then you have probably a serious problem with your OS…
Help > Audacity Support > Install FFmpeg.
Your link is the one I went to, which for Windows ends up at the 403 error from https://lame.buanzo.org/FFmpeg_5.0.0_for_Audacity_on_Windows_x86_64.exe.
As I say, I work with video in every format under the sun which work fine on my OS. I have YT paying now. But not this one. 
On Firefox & Waterfox. Brave runs through the “Verification” cycle endlessly. Antivirus is off.
So I downloaded the FFmpeg package from GitHub, but I still need to know what to do with it, so I found that here - How to Install FFmpeg on Windows: A Step-by-Step Guide
Now it is installed (checked in CMD) and I go to Audacity to direct it to the FFmpeg library & it asks for ‘avformat.dll’… but there are no .dll files in the FFmpeg directory (C:\ffmpeg)! 
Stumped.
Audacity requires it’s own version of ffmpeg. Use the link in post 2 of this thread. It works for me.
Thanks. Post 3 was why that didn’t work for me, but I just tried again & it worked! 
