Windows Installer package is invalid or cannot be opened as a valid package
1620 is a package-validity/opening error; verify the installer with the publisher instead of applying generic Windows repairs.
What it means in this context
Microsoft defines Error 1620 (ERROR_INSTALL_PACKAGE_INVALID) as the installation package being unable to be opened and directs the user to contact the application vendor to verify it is a valid Windows Installer package.
What is known, and what is not proven yet
Keep observation, evidence and conclusion separate before making a higher-impact change.
Windows Installer returned 1620 for a package.
Package provenance/version and reproducibility with a fresh official copy.
Installer package validity.
Publisher confirmation that the package is valid for this Windows/device context.
Use a fresh official package and stop bypass attempts.
Software publisher/package administrator.
- Verify the installer came from the official publisher.
- Download a fresh copy rather than reusing a partially downloaded/archive-extracted file.
- Confirm the vendor intended the file for your Windows/device architecture and deployment method.
- Avoid modifying the MSI to bypass validation.
Replace or validate the package with the publisher
Low riskWhy: 1620 points to package validity rather than a generic system-file problem.
- Discard uncertain/corrupt copies.
- Download the current official installer.
- Confirm checksum/signature when the publisher provides one.
- Contact the publisher if the official package continues to return 1620.
When not to use this record
Do not disable signature/security controls or edit MSI internals to force an invalid package to install.
If it persists
Use a different scoped MSI record only if the package begins opening and returns a different code.