Is this the Fnord VP9 plugin? Afaik there is no official vp9 support for AME in the latest CC version.
Third party plugins aren't supported, and as such I don't think there's much help available online. It also makes it hard to say why this would crash - it might be a hardware trigger, anything software related, encoding related, or the way the plugin hooks into the current CC version of AME. (I believe it was developed for CS6)
(the last push on the project's github was 8 months ago)
I don't know of any encoder that handles vp9 natively of the 'big ones'. Only ffmpeg has an encoder that is maintained.
Therefor, I tend to do vp8 and vp9 using ffmpeg (or any of the GUIs if that is more convenient, particularly VLC for (batch)converting should be using the latest libraries for the vp9 codec, and has cross-platform versions)
To enable this, compile ffmpeg with --enable-libvpx and it'll give you the vp8 and vp9 options ffmpeg version 3.4.1 Copyright (c) 2000-2017 the FFmpeg developers
built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4.1 --enable-libvorbis --enable-libvpx
DEV.L. vp8 On2 VP8 (decoders: vp8 libvpx ) (encoders: libvpx )
DEV.L. vp9 Google VP9 (decoders: vp9 libvpx-vp9 ) (encoders: libvpx-vp9 )
I built on mac with Homebrew, using the --enable-libvpx, --enable-libvorbis and --enable-libtheora switches.
Hope this helps.