so i was thinking sins there is a problem whit uuid and cracked servers wouldn't it be possible to change the uuid for cracked server whit there ip like when they join and it sees ip and makes it to a uuid so if they change there name they still have the same data as before but there one more problem what if they static ip well idk
??? The current cracked uuid system is ok. Making the uuids ip-based will make every user with a non-static ip (nearly all) lose their data daily.
Name changing isn't supported by offline mode, it gets the UUID from the name, as Janmm14 said, it wouldn't work any other way.
There is nothing to fix. There is no way to track offline mode players, so it's your loss if you decide to go the cracked route.
And tracking players by their IPs isn't a smart decision since a lot of ISPs use dynamic IP addresses, so users could have a different IP address depending on the week, their ISP, and whether or not their connection has been reset.
Hardly any ISP offers static IPs without paying a fee. My DSL connection here in Canada changes about once a week unless I reboot the modem.