Problem is found and fixed. It was in ~./local/share/ubuntu-system- settings folder. Somehow normal structure of this folder messed up.
Normally, there must be 1 file "updatestore.db" but when it broke there were no such file, only an empty folder "Pictures". (???) How can it be possible? Manual intervention is excluded. I didn't even open hidden folders for weeks, I didn't make my system folder RW, etc. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1617290 Title: OS and apps can't update To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/system-image/+bug/1617290/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs