mepj to wav conversion is typically searched by users looking for a way to export projects from Movavi Video Editor to get just the audio track saved as PCM audio / WAV file. Such export is actually only possible with the proper version of Movavi Video Editor (version 23.2 or above) and only if you have all the original multimedia data referenced in the projects. Single .mepj file is pretty much useless on its own, so if someone sent you the file, ask them to do the export themselves.
Updated: July 24, 2023