Client Automation - All Versions
The actual error for 1620 code is "ERROR_INSTALL_PACKAGE_INVALID". Based on Microsoft's database, this error is described as:
"This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package."
This means that the source is corrupted, probably the Client Automation's ISO was not downloaded correctly. Downloading the ISO one more time will solve this error.
List of all MSI error codes:
https://docs.microsoft.com/en-us/windows/win32/msi/error-codes