Problem

When you try to install Citavi you receive the following error message: "This installation package could not be opened."

Cause

The Windows Installer service is disabled.

Solution

In the Windows Control Panel under Administrative Tools > Services , check whether the Windows Installer service is enabled. If not, click Start the service :

If that doesn't help, re-register the Installer service:

1. Press WIN+R .
2. Enter cmd and click OK .
3. Enter msiexec /unregister and press Enter .
4. Enter msiexec /regserver and press Enter .
5. Restart your computer.
6. Install Citavi.