Has anyone had success installing MS Office 2016 ProPlus from a network location with Zenworks while the client machine is logged out?

I am just trying to call setup.exe (silent installer) from a network location using dynamic administrator and a username that is valid both on the machine and our network server. The package installs fine if the client machine is logged into any user account, but fails with:
Error launching "\\xxxx\xxxx\apps\Office2016Silent\setup.exe ". Windows error: The directory name is invalid. --if attempted while the machine is logged out.

I have also tried packaging w/ Admin Studio (failed miserably - resulting install won't run -licensing errors)
And tried copying the whole source directory into zenworks and then installing that on the target machine to run the setup.exe locally, but that fails too.

Any help is much appreciated...