Thank you, I appreciated the information.
You originally comment mentioned that the error message shown by the game stated it was looking for an ".ogg" audio file and you believed that it should of been a ".rpgmvo" audio file.
(note: a ".rpgmvo" audio file is just an encrypted copy of a ".ogg" audio file)
When the developer builds a release of their RPGM game they can choose to encrypted the audio & image files, and those releases will contain ".rpgmvo" & ".rpgmvp" files, this is what the developer of this game has chosen to do. The developer may also decide to bundle the release as a self-contained Packaged executable, and this game's developer has done this with some of their past releases.
When an 'Uploader' adds a Packaged and/or an Encrypted release RPGM based game to this site they sometimes decide to first Un-package and/or Un-encrypt the contents of the game, this makes it easier for the player to directly open the audio & image files. If they un-encrypt the files they need to let the game engine know that has been done, and the two settings I mentioned in my previous post (about this topic) is how they go about doing that.
You can't use an ".ogg" file in a RPGM game that is configured to use encrypted audio, and you can't use a ".rpgmvo" file in a game that is configured to use un-encrypted audio. So if you are running an encrypted release of this game then you either need to obtain a ".rpgmvo" copy of the audio file, or you need to change to using an un-encrypted release of this game. There are tools that you can use to un-encrypted the release you already have, searching this site will lead to them.