Invlid IP address?

I am trying to edit info for one of my connected devices with a reserved IP address in the (cisco) router, but when I try to save I get an "Invlid IP address, please input again" alert (see screen capture below), and the info doesn't get saved. I am just adding something in the comments section, I am not changing the IP address or anything like that. Any idea of what is going on? This has been happening for a while. Why would the address be "invlid" [sic] (I presume that means "invalid") if I added it a few months ago and didn't have any problem at that time?