Sometime you might see an error message when trying to install or update the Agent:
This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package.
In most cases, this happens with the Silent Agent with a MSI installer.
You might see this message for a number of reasons:
Your antivirus software is blocking the installer.
You do not have the account privileges to execute software installations.
The installer file is corrupted.
Windows UAC (User Access Control) is working in auto-accept mode.
Windows doesn't allow downloading the Agent via the Command Prompt or PowerShell (due to SSL/TLS limited support) and this error will be displayed during the MSI-package deploy via the command line or remotely (On-Premise).
Follow one of the remedies below according to the cause:
Disable your antivirus software temporarily or add exceptions. Check out the Antivirus Configuration Guide for more information.
Try running the installer as an administrator (right click the installer file and select the Run as administrator option).
Download the installer again (make sure you selected right type of agent (Hidden/Revealed), right OS (Windows/Mac) and right executable (32/64 bit - MSI).
Use the UAC in active mode or disable it. Check out Windows help or ask your administrator to learn how to change the UAC settings.
Correct the agent package link so it will be HTTP rather then HTTPS to avoid SSL/TLS error.