Error 1620
This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package.
Windows Installer opened the file and found it was not a valid MSI. That is different from error 1619, where it could not read the file at all.
What it actually means
The distinction matters. 1619 is an access problem; 1620 means access worked and the contents were wrong. In practice that usually means a corrupted download, or a file that is not an MSI despite its extension.
How to fix it, in order
Ordered by how often each one is the answer, not by how clever it sounds.
- 01Verify the file hash against the publisher's published value. This settles immediately whether the bytes are correct.
- 02Re-download if the hash does not match, or if none was published and the size looks wrong.
- 03Check what the file actually is: open it in a hex editor. A real MSI begins with the compound file signature D0 CF 11 E0. An HTML error page saved with an .msi extension starts with readable text.
- 04If it was extracted from a larger installer, the extraction may have been incomplete. Extract it again.
1619 and 1620 are not the same error
Guides routinely treat them as interchangeable. 1619 means the package could not be opened at all, usually a path or access problem. 1620 means it opened and the contents were not a valid package, which points at the file itself.
Common questions
- What is the difference between error 1619 and 1620?
- Error 1619 means Windows Installer could not open the file, typically a path, permission or missing-file problem. Error 1620 means it opened the file and the contents were not a valid MSI, which points at corruption or a mislabelled file.
Before you retry the installer
If the package came from anywhere other than the publisher, confirm it is the file they actually shipped. Check its SHA-256 against our index, which settles in seconds whether you are debugging an installer or a damaged download.