ZenHAX

I have an issue here. I am converting commonly used .mp4 files to .avi via VirtualDub, I use video codec VP60, audio bitrate 44100 Hz, stereo and 16-bit, bicubic scaling, but when I want to convert this exported .avi to .vp6 using EA VP6 Builder, Error 9 appears. I don't quite know why it happens.
The only thing I know is that when input file has directory C:/file.avi, progress bar starts, but in the end the same error appears.

What else do I have to do to make custom .vp6 video?

IIRC the audio stream must be converted separately so you must export the avi file without the audio then supply the audio later by exporting it to wav then convert it with Sound eXchange (sx.exe) tool

Where can I find Sound eXchange?

You can find it here at this post: viewtopic.php?t=8868#p40480

The question now is how and to what convert. I see the manual, but if you say that audio needs to be converted separately, I want to know how to convert audio to be used to this process.

Export the audio stream as wav file (You can do this with VirtualDub, go to "File" then "Save WAV") , export it to VP6 avi without audio (Select "No audio" from the "audio" menu), then run the conversion with SX like this:

sx -sndstream -eaxa_blk source.wav -=source.asf

Change "source.wav" and "source.asf" to the name of the audio you just exported from the video file.