Problem

When attempting to update Citavi, Windows Installer tells you that an error occurred and shows you where to find the setup log. The log includes the line: MsiInstallProduct returned '1638'.
 

Cause

A folder required for Citavi installation is either missing or read-only.
 

Solution

Completely uninstall Citavi, then reinstall it. Your projects and settings will remain intact.
 
A) Uninstall Citavi
 
1. Copy the following command to the Clipboard:

Citavi 5:
msiexec /x {7EB278FB-0C3C-445E-8665-4A6CDD9B794E}

Citavi 4:
msiexec /x {CC0A85B2-734A-45B3-B678-05F6A6499AC7}

Citavi 3:
msiexec /x {e12c6653-1ff0-4686-adb8-589c13ae761f}
 
2. In the search field, type cmd.exe and right-click the cmd.exe program found, then click Run as administrator:

 
3. Right-click in the cmd.exe window that opens and click Paste to paste the command from step 1.
 
4. Press Enter to run the command.
 
B) Reinstall Citavi
1. Download the latest version of Citavi: www.citavi.com/download
2. Run the setup file to begin the installation.