While working on a project in which I wanted to automatically process any CSV files uploaded to the media library I encountered some issues with WordPress.com not allowing this file type.
After an upload, WordPress.com kept buggin me with:
1 file could not be uploaded because the file type is not supported.
upload_mimes seem to be ignored by WordPress.com until….
You switch from Default View to Classic View
Yep – that’s right. When switching to Classic view, you suddenly have a lot more freedom in which mime types are allowed for uploading and WordPress.com respects the
upload_mimes filters in this view as well!
Easy as pie – but it’s one of these things you just have to know..