Ubuntu 15.04 (Vivid Vervet) reaches End of Life on February 4 2016 so dont expect any fix there, but think to use a newer release. Note too that wily will also reache EOL at the end of July (12 days ahead !!!), so make the jump to xenial to get a LTS.
You can do this a fresh installation, as the vivid -> xenial upgrade may not works out of the boxe (too much changes between these two releases) ** Changed in: apt (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1603623 Title: apt-get update returns error: Checksum mishmash To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1603623/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs