rm .Xauthority and relogin has solved the issue. used python3-xlib_0.14+20091101-1ubuntu3_all.deb
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1482844 Title: Caffeine can't connect to display since updating Trusty to Vivid kernel and X (HWE) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/python-xlib/+bug/1482844/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs