Hello,
If you type something other than "/" commands into the server console the server crashes, because the on_console_chat event object doesn't contain a player_index when the chat message comes from the server console.
The solution:
script.on_event(defines.events.on_console_chat, function(event)
game.write_file("ChatLog.log","\r\n[" .. (event.player_index and game.players[event.player_index].name or "Server") .. "]" .. event.message, false, 0)
end)
Also, note the ", 0" at the end of the function! No need to save the log files on the clients as well. Only on the server is sufficient.
Chris
P.S.: I even went a step further and just copied the four event handlers from your control.lua directly into the control.lua of the savegame. No need for my clients to dowload an additional mod ;-)