NVBU upgrade does not complete, and a popup window looking for the file netvault.msi, with "The f (4046531)

In this example, we are upgrading the current "NetVault Version 8.5.0" running in a Windows machine to the latest NetVault version 8.6.X.

We decompressed the "netvault-R2012MAY21-JUNO-Windows.zip" file which created a folder named netvault in the desktop.

We navigate into the netvault folder for the NetVault version 8.6.X and clicked on the Setup.exe to initiate the upgrade from NetVault 8.5.0 to the latest version 8.6.X

While upgrading NetVault from the version 8.5.0 to the latest 8.6.X, the operation stopped with a pop up message looking for the file netvault.msi :

"The feature you are trying to use is on a network resource that is unavailable"

If we browse to the current netvault version 8.6.X installation folder containing the current netvault.msi, the installation will stop again with a new pop up window:

"The file c:\...\netvault.msi is not a valid installation package for the product NetVault Backup"

"Try to find the installation package netvault.msi in a folder from which you can install NetVault Backup"

When clicking on Ok, the pop up windows will go away and the upgrade process will stop, leaving the current netvault installation intact.