Hello there, I’m new here in the forum, but I hope to get along well with all of you and -why not- give some help improving Ubuntu MATE for Arm (I’m actually falling for this platform).
I installed Ubuntu M on my Pi 3 (32GB MicroSD) few days ago, updated the system and kernel, but everytime I try to perform a complete installation of language (Italian), a message saying something like “Chek your connection” pops up. My connection works, in fact I did every update available, except this one, with the result I still have an english layout on my keyboard… can anyone give me a hint?
Thanks in advance! 
Ok, solved. All I did is just add mirrors in the repository list and everything went fine. 
As for the keyboard, added a new layout and removed the previous.