MPEG-4 Audio does not work?

OK so what I'm trying to do is import music that is MPEG-4 the same file type as the music that's in the RTP. For reasons unknown the project does not show it within it's contents no matter what I do.

Anyone got by this stupid problem?

The default resources are not MPEG-4, they're are OGG Vorbis or AAC M4A. MPEG-4 (mp4) files are, unfortunately, not supported. You should be able to trick the editor by renaming them to .mp4.ogg, or similar, however the editor itself probably won't be able to play the files. The games, however, should work fine, as the desktop client is made with the open-source base to the Chrome browser.

How come when I check the files properties they are listed as MPEG-4 Audio (.m4a)?- the same file type as the ones I imported but still will not accept them?

To have audio tracks display in the editor they must end in .m4a or .ogg (you must have one of both)

The audio inside the .m4a container must be AAC audio. The audio inside .ogg muist be Vorbis audio.

AAC audio is used on mobile devices. Ogg is used on desktop devices.

Where and what can I do to convert files for .ogg?

You should have the original files.

To convert audio files to ogg vorbis

ffmpeg -i input.wav -acodec libvorbis output.ogg

To convert audio files to aac inside a mpeg4 audio container

ffmpeg -i input.wav -acodec aac output.m4a

If you're cross-transcoding, be aware that you lose quality every time you convert a lossy format into a lossy format. RPG Maker MV came with ogg vorbis (ogg) and aac inside mpeg-4 audio (m4a) of all tracks.

You can have ogg without m4a, but you cannot have m4a without ogg.  When you export, only the one that's needed for your selected device will be included.

m4a cannot be read by editor. only oog... so you need both oog (for working in editor) and m4a (to use it in android / ios build).

think of oog files as a placeholder inside editor.