I’ve taken a look at the file in question, the end doesn’t seem to be terminated correctly, so when we request the decoded size of the file it returns 0. I’ve cross-checked this with the latest Ogg Vorbis reference on GitHub and that code returns the same invalid result. I’ve also cross-checked with MediaInfo and can see it doesn’t know the length either.
Most Ogg Vorbis players don’t care much for length and simply stream the file, which you can do with FMOD::CreateStream. However to decompress into memory FMOD needs to know ahead of time the size of the decompressed file.
My suggestion would be to use a different encoder (or perhaps a newer version). In the past I’ve used OggDrop without issue.