I have this issue as well. Gives the read only error and crashes, specific to the 0.10.1. save. Also, if I go into the app data folder to remove the read only setting on any factorio folder in this specific location, I can, but it just reverts back to read only as soon as the folder properties window closes.
Confirmed I have this issue as well. Created a new( default Play -> New Game -> (default game settings) -> Generate) game and saved it. Went back to the main menu and attempted to load the game and got the same error (different username obviously).
I'm also getting this, but I noticed that my save from the previous version loaded fine, so I tried saving THAT to a different name with 0.10.1 and loading it. It works, surprisingly, so combined with that other thread, it seems likely to be related to replays.
Same Problem here.
I had the Installer Version of the old Factorio build installed. For the 0.10.1 i downloaded the ZIP Version and just copied over the old files, played for an hour and saved. Save Game didn't load.
Here is how i solved it.
I deinstalled and deleted all the contents in the Factorio folder except for the save games. (make a backup of them).
Then i downloaded the 0.10.1 as the installer version (not just the ZIP), installed it and the old savegame which wouldn't load, loads now.
Hope this works for you