When a video is uploaded to AdultFolio, it's run through a process to turn the video into 3 different quality levels (where appropriate), as well as generate the thumbnails and gifs for it.
In around 15% of video uploads, this process wasn't working effectively and the video would be unplayable, despite being live.
The processor that handles this has been rebuilt from the ground up and is now live on AdultFolio. This should prevent these errors from occurring going forward.
If you do happen to see any videos from today's date that are unplayable, please do raise a support ticket :)