I keep seeing this in my servers error log:


[Thu Aug 12 12:25:54 2010] [error] [client my.ip.here] File does not exist: /home/example/public_html/401.shtml

Does anyone know:

#1: What this file does?
#2: Why am I missing it?
#3: Is it Zen Cart related?
#4: Do I need this file?

Thanks