I can't run Cisco packet tracer 7.1 on Ubuntu

It seems that you are using CPT 7.1 on Ubuntu 16.04 LTS.

I have found a nice guide to run CPT.

Steps:

  1. Install CPT as you have already done.
  2. Download correct version of library libicu52 (for example for amd64)

    cd /tmp
    wget http://mirrors.kernel.org/ubuntu/pool/main/i/icu/libicu52_52.1-3ubuntu0.8_amd64.deb
    sudo dpkg -i libicu52_52.1-3ubuntu0.8_amd64.deb
    

3 . Launch CPT with the packettracer.

Update: this procedure works with CPT 7.1.1 too.