lib64expat1 software package provides XML parsing C library - runtime library (64bit), you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install lib64expat1
lib64expat1 is installed in your system.
Make ensure the lib64expat1 package were installed using the commands given below,
$ sudo dpkg-query -l | grep lib64expat1 *
You will get with lib64expat1 package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Libraries |
| Package | lib64expat1 |
| Version | 2.1.0-7ubuntu0.16.04.2 [i386], |
| Description | XML parsing C library - runtime library (64bit) |
| Sub Section | Libs |