Yes, your FAQ does fix the IOEXCEPTION: Too many files open.
I'm reporting a different bug in this thread - it just so happens that the last one wasn't fixed and is occuring as well. Please mark it as such.
The different bug I am reporting here is about ghost players, unclosed connections, zombies chasing disconnected players and "ping unknown client".
This is not a fix for windows dedicated servers. The logs are from windows servers. The effects of this A21 bug where ghost players are online, time still passes when no one is online still happens. A fix for this isn't listed in the FAQ as it is not present in A20.7, but in A21.