TMPGEnc: HOW TO USE *.AVS files in TMPEGenc
 

i use *.avs script w/tmpeg so there´s my experience
must disable directshow in tmpeg
when making the *.avs script w/notepad, save as ALL FILES not text files
before the instalation of Avisynth remove ALL avisynth.dll from PC
at last try to «install» to your Windows registry the Readavs
to me works
2man