I'm trying to convert an MP4 video to Webm muxer, for uploading to the Hebrew Wikipedia, and I get this error message:
(https://i.postimg.cc/WbNSXS2r/Error-converting-MP4-to-Webm-with-Avidemux.png)
How I can convert the MP4 to Webm correctly without errors?
This is not possible with Avidemux due to VP9 (or VP8 at least) encoder missing, please have a look at FFmpeg (https://trac.ffmpeg.org/wiki/Encode/VP9). An Avidemux VP9 encoder plugin is on my todo list, but it most likely won't be in any usable shape in time for the next release.