Unable to install or update FixMe.IT Expert application

Problem

You may receive one of the following error messages upon attempting to update or install the Expert application:

This installation package could not be opened. Verify that the package exists and is accessible, or contact the application vendor to verify that this is a valid Windows Installer package.
This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package.
The installation source for this product is not available. Verify that the source exists and that you can access it.
A fatal error occurred during installation.
This action is only valid for products that are currently installed.

These issues may occur when:

The Windows Installer database file (.msi) is missing from the Windows Installer cache, which is located in the following folder: %windir%\installer.
The Windows Installer database was corrupted during a previous uncompleted Installation or Uninstallation procedure.
Your computer registry is corrupted and/or cluttered.

To resolve this issue, you need to do the following:

Uninstall all existing FixMe.IT Expert files from your computer using a cleanup component. In order to do this, download and run FixmeitExpertRemover.exe with administrator rights.
Download and install the Expert application using the following Windows Installer package (FixMeitExpert.msi): https://fixme.it/TechinlineExpert.msi

Affected operating systems: