Board Thread:Support Requests - Getting Technical/@comment-32381744-20171010140423/@comment-27345308-20171010155407

Weird, it says the same to me but I was just able to upload an OGG file. Are you sure you didn't download an  file from the internet and just rename it to  ? Though that MIME checker is telling me  in Chrome for actual OGX files so it could also be a bug which you can report through Special:Contact/bug.