6to4 - fixed wrong IPv6 "link-local" address generation , what does it means?

I already get email from mikrotik and give information about upgrade MikroTIK RouterOS 6.39.2

What’s new in 6.39.2 (2017-Jun-6 08:01):

*) 6to4 - fixed wrong IPv6 “link-local” address generation;

but I still confused about this.. what is differents? I already have screenshoot..

6.38.5
6.38.5 sit6to4.jpeg
6.39.2
6to4.png
who can give explanation to me :slight_smile:

See here.

Thanks sir.. :slight_smile: