The agent deployment is not able to connect to $-shares. If you've deactivated the admin shares like c$, d$ and so on the agent deployment will not be able to transfer the installer exe to the target device.
I have run into this several times... Security policies will disable the C$ default share but often times leave the admin$ still open...
Udit, can you see if you can UNC into a customers device using the admin$ share? If yes you can modify the rollout server's config file to point to admin$ first. That has worked for me in the past.