Ok, it seems it was failing because beside user ftp there was user "ftpdrop" defined on the system. After removing user "ftpdrop" it installed correctly.
-- package vsftpd 2.2.2-3ubuntu7.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 3 https://bugs.launchpad.net/bugs/646054 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
