Failed to fetch

Good morning, we wanted to download the PDF Version of our document, but nothing is working. We tried on different devices, but on all of them we get the message: Failed to fetch. 
Normally we download our documents from the App on our computer, then we tried on the iPad, on several browsers, but nothing, it does not work. What can we do, because we worked a lot on that document and now we can't download it. It's really urgent. We also tried to duplicate, but nothing.

Thanks for helping us.