If you have trouble transferring assets to the Secondary machines in LightNet, this will most likely be visible in the LightNet Transfer popup. If you hover your mouse over the progress bar of each non-transferable asset, you will see a more detailed description of what the error is.
Another way to figure out what is causing the error, is to look in the LightAct Logs window. Here, you can see the actual robocopy command that LightAct used when it tried to transfer the assets.
If you run it directly in the cmd window, you might get additional information.
For example, in the case of getting The user name or password incorrect message, you will most likely have to set up the sharing correctly.