Unable to convert Avisynth script in ffmpeg I tried create a video file from the AviSynth script using this command (in Windows 7):

ffmpeg  -i  file.avs  file.mp4


and I got this message:

[avisynth @ 05000e60] AviSynth version is too old. Please upgrade to either
                      AviSynth 2.6 &gt;= RC1 or AviSynth+ &gt;= r1718.
                      file.avs: Unknown error occurred


Very clear recommendation (as I use AviSynth+ 0.1 (r1576, x86)) but I'm not able to find an newer version, neither for AviSynth, nor for AviSynth+.

Nevertheless, it was probably only an recommendation. The most important part is indeed this:

                      file.avs: Unknown error occurred


So I changed the content of the file.avs - I put only one command into it, enough simple and stupid, so my file.avs now looks like:

version


No change. The same message. So I kindly ask for an advice what to do.

(I tried it with versions 3.2.2 and 2.8.4 of ffmpeg, both of them report  --enable-libxavs in their configuration and D  avisynth  AviSynth script in their file formats obtained by ffmpeg -formats.)
From FFmpeg source code:


  On Windows, FFmpeg supports AviSynth interface version 6 or higher.
  This includes AviSynth 2.6 RC1 or higher, and AviSynth+ r1718 or
  higher, and excludes 2.5 and the 2.6 alphas.


From doom9:


  The decision to drop support for anything below 2.6 RC1 was due to
  catastrophic header incompatibilities between 2.5 and 2.6 RC1* and the
  maintenance burden (and potential licensing minefield that could mean
  any additional 2.5 support would violate GPL) that would be incurred
  by trying to continue to support 2.5 while using properly updated 2.6
  headers.




Get AviSynth+ r2420 from 
https://github.com/pinterf/AviSynthPlus/releases/tag/r2420-MT