A McAfee Agent upgrade fails when you try to upgrade to a later version while invoking the local install from a Windows PowerShell.

NOTE: Silent installs also fail.

You see this issue on systems that have either or both of the following products installed:

• Endpoint Security Threat Prevention
• Adaptive Threat Prevention

The command below is executed in PowerShell:
 
NOTE: The Frame Package name can be different, and depends on the naming convention in the environment. 

The McAfee Agent displays the error message below:

The following applications should be closed before continuing the installation.

Administrator: Windows PowerShell

Cancel   Retry  Ignore

You see the errors below recorded in the MFEagent.msi log file:

Info 1603.The file C:\Program Files\McAfee\Agent\trex.dll is being held in use by the following process: Name: masvc, ID: 8700, Window Title: (not determined yet).  Close that application and retry.
MSI (s) (A0:C8) [10:12:31:774]: 7 application(s) had been reported to have files in use.
Info 1603.The file C:\Program Files\McAfee\Agent\ssleay32.dll is being held in use by the following process: Name: masvc, ID: 8700, Window Title: (not determined yet). Close that application and retry.