My anti-virus is amongst those that scans files that get read for virusses, your saveConfig function does not take this into account, and crashes the game if it tries to save the config while the anti-virus is scanning it.

Only mods that rely on codechicken.lib.config.ConfigFile.saveConfig for their configs crash when this happens.

Please fix this issue, It is a real annoyance to have to shut down and reboot my anti-virus every time I start minecraft, switch worlds, wish to access the NEI settings menu, etc.

Which antivirus is this?

Trent Micro Titanium