There are a few scenarios where previews will fail to show:
- The person accessing the file could be using an older browser which doesn't support media playback. For example, older versions of Internet Explorer. To ensure they have at least the ability to download files we display basic version of the download page that won't show previews.
- For more modern browsers that don't natively support media playback, we require Adobe Flash to enable previews. If the user doesn't have this installed they will see a placeholder requesting that they install support for this.
- If the downloader accesses the files before out system generates previews, they will see a placeholder with the text Generating previews.