I am running RhodeCode on an Apache instance listening on a port other than 80 on my Windows Server 2012 computer. It appears that when IIS proxies to Apache, a port number is appended to the IP address, and that causes an error when the Allowed IP Addresses system tries to parse it. I have confirmed that the error occurs only when a reverse proxy is in place. Going to the IP Address:Apache Port 'url' works fine.
Issue #737 wontfix