Many have been having issues sending snapshots from in-world to their SL web profile feeds and the latest news is that the problem is still being working on by Linden Lab. Currently there is no estimated time on when it will be fixed. All we can do is be patient and try to find another way around it.
Simon Linden said this at a recent Simulator User Group meeting on 14th January in Second Life.
It has to do with authentication under the hood when getting the credentials and then using them to fetch the snapshot config info
Linden Lab are working on it and hopefully it will be resolved very soon. This is the problem when trying to post a snapshot > a few moments it fails to send the snapshot.
Failed message appears saying > “Failed to upload image to your Profile Feed“
I hope this issue gets fixed very soon because I love uploading my adventures in Second Life with my friends on my SL web profile feed.