There is currently a problem with the Object Storage from OVH that is used to serve media files for Masto.host and this is affecting both loading uploading of media.
They are already working on it: http://travaux.ovh.net/?do=details&id=47465&
Sorry about this. Hopefully they fix the issue soon. I will post here when I know more.
Ici, on communique, on échange, on sympathise autour du Roller Derby. Toutes les thématiques seront les bienvenues dans le respect et la bienveillance de chacun. A très vite ! Here, we speak, we make links and sympathize about Roller Derby. You can publish everything with respect and friendliness of everyone. See you soon !