saving causes panic

[Criptc]

When you try to save the game, it panics and gives this output

PANIC!!
panic occurred: "<no further information>" in file 'src/gamefile.rs' at line 63
PanicInfo { payload: Any { .. }, message: Some(open(doomsav0.dsg, 0, 1048240) unimplemented), location: Location { file: "src/gamefile.rs", line: 63, col: 5 } }

which i assume means you haven't got it to save in the browser local storage yet