On my Proboards we use a plugin (IP Lookup 0.0.7 L ) that looks up the IP address on this site. Recently WMIP began to crash on most of the new IP formats - I don't know enough about the new IP addresses to be able to spot where a formatting error is. I just know they look different lol.
Here is an IP that reports the message below:
2601:6c3:4200:6f50:7a:1
Page Not Found
We were unable to find the page you were requesting. You can either search for what you were looking for, use the navigation above, or check some of the frequently asked questions or our glossary.
If you were searching for an IP address it was improperly formatted.
Do we think the trouble lies on the Proboards plugin side?
That's IPv6 format but the example you are providing is missing 2 segments.
It should be in the format of aaaa:bbbb:cccc:dddd:eeee:ffff:gggg:hhhh. Leading 0's can be dropped and single or multiple segments in a row of 0000 can be dropped and replaced with ::