Problem solved itself. I realised I had installed VirtualBox, but system crashed during installation of this package. After three restarts of system I ran 'apt-get update' and I got no error message. The only one thing I had to do was reinstall VirtualBox. I hope this will help others who have the same problem
-- Synaptic or other package manager on Ubuntu crashes after it launches. https://bugs.launchpad.net/bugs/113666 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs