With version of RMC 5, we recommend using the WinPCap network monitoring software. WinPCap is more robust and has fewer collisions with other software. Additionally, WinPCap supports a wider range of network devices. If RMC 5 is not downloading any media despite monitoring being turned on, WinPCap perhaps didn’t identify the correct network interface. Go to Settings->Internet->Monitor and try the other available network interfaces in the WinPCap section.
Right above the WinPCap section, there is an option to install the legacy Network Monitor. Again, we no longer recommend it, but it is necessary for some people (if behind a proxy for instance).