Troubleshooting error: Package system is broken or has unmet dependencies

Introduction

Problem description

This is the troubleshooting procedure for the error message the package system is broken/unmet dependencies.

When updating Ubuntu in the NavVis software or with the UI Updater, the update fails with an error message similar to the following:

The package system is broken
Check if you are using third party repositories. If so disable them, since they are a common source of problems.
Furthermore run the following command in a Terminal: apt-get install -f
Transaction failed: The package system is broken
The following packages have unmet dependencies:
navvis-mapping-ui

Dependencies of NavVis software might not be configured correctly (e.g. only partially updated...). In the above example, some NavVis packages were updated to 2.6.0 but unpacked, others were still at 2.5.0.

Results from executing the navvis-diagnosis command in an Ubuntu Terminal can bring similar messages to the following lines:

Scope

Applies to: MMS System Software & Desktop Processing Software (all software versions), Ubuntu 18.04

Troubleshooting procedure

1 Check the software and updates application

1. Check the software and updates application which is pre-installed on Ubuntu to see if the updates are selected. 

2. If the workstation has not yet installed NavVis software, check if the following software updates are selected under the Ubuntu Software tab:

3. Also, check the Updates tab and ensure the following options are selected:

4. Make sure that the Other Software tab has relevant data selected.

5. Leave repo.navvis.com (or repo2.navvis.com for software version 2.11.0 and higher) entries unchecked, so you can clean the system software without facing errors from NavVis's related repositories:

sudo apt-get update
sudo apt-get dist-upgrade

6. Afterwards try to install Navvis software again using the official installation scripts.

2 Fix broken installation

1. Open a terminal and run the following:

sudo apt-get update
sudo apt-get dist-upgrade

2. The last command will return another error message:

(...)
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

3. To fix this, run

sudo apt --fix-broken install

4. If that passes, run again

sudo apt-get dist-upgrade

5. This might fail because dpkg is still blocked:

...
Errors were encountered while processing:
navvis-jetty9 
navvis-web
navvis-trolley-m6 
E: Sub-process /usr/bin/dpkg returned an error code (1)

6. To fix this, run:

sudo dpkg --configure -a

sudo apt-get update
sudo apt-get dist-upgrade