Hey guys! Thanks for the quick reply.
So to give you more context, my guess is that this issue is happening cause the environment is only reachable via VPN, and to preview a document we use Google Viewer. As google can't open the link, we aren't able to display the document. If I open the "location" directly from the browser it works, but if I use the link using gview (https://docs.google.com/gview&url=xxxx) it doesn't work.
Regards,
José