issues with ffmpeg

[lyapounov]

Hello

I helped a friend who just switched to minimServer 2

He has a DS214 play

Install went smoothly; until I installed minimstreamer.

Then suddenly, he would not accept the ffmpeg downloaded from https://johnvansickle.com/ffmpeg/ the file ffmpeg-release-i686-static.tar.xz

I put the ffmpeg file in /volume1/MinimServer/opt/bin/

It was working before, but now when I type in stream.converter this value
/volume1/MinimServer/opt/bin/ffmpeg

it says in red:

"Converter not installed; correct value and retry"

Surprisingly, when I put nothing in this field, it automatically replaces by ffmpeg, and I don't have anymore the red message. This is weird as I thought that by default it would use the ffmpeg downloaded

Now, I know that it is using the synology ffmpeg because when I add in stream.options

convOut=-af aresample=resampler=soxr:precision=33:cheby=1:dither_method=shibata

then the red warning comes back... Which means that it is using the synology ffmpeg, not the one in /volume1/MinimServer/opt/bin/ffmpeg

What am I doing wrong ?