Not sure where to post broken saves, but this seems like the right place.
So I played this save a few days ago with my friend and just now when I tried opening it, it seems corrupted.
I downloaded my save from factorio.i-craft.de (a free Factorio hosting server), because my server didn't seem to want to start up, but it seems that the save file has been corrupted.
This may be because the website has messed with it, but you guys probably know more about them then I do.
'Opening zip C:/Users/welfj/Appdata/Roaming/Factorio/saves/MP_server.zip failed: Bad zip file' is the error message I get when I'm trying to open it as a single player world.
I don't have any autosaves of this world lying around nor any back-ups, so hopefully this world can be fixed.
See the posted attachment for the save file.
P.S. It would be nice if the developers could implement a ctrl+c function for errors inside Factorio, so I wouldn't have to type them out, but no biggie.
Thanks for your time!