Summary
When installing or uninstalling Laserfiche, you may receive the following error message:
This patch package could not be opened. Verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid windows installer patch package.
Cause
In most cases, this indicates corrupted registry keys.
Resolution
Microsoft offers an automated Fix It tool for troubleshooting this type of Windows Installer issue. Please see the following Microsoft Knowledge Base articles for more information.
http://support.microsoft.com/mats/Program_Install_and_Uninstall