When a Netop File Transfer connection is established to a Host running on a system with UAC enabled it is not possible to view or access the mapped network drives on the Host in the Netop File Manager Window. This symptom is caused by the way UAC filters the tokens used to access these drives.  The solution to this issue is to create a new registry key entry.  The instructions are outlined below.

Due to the risks associated with editing the Windows registry this task should only be performed by your system administrator.   Be sure you have a backup of your system’s data and registry before you begin.

For additional details on this behavior and resolution please visit the following link from Microsoft TechNet.
Some Programs Cannot Access Network Locations When UAC Is Enabled

To configure the EnableLinkedConnections registry value
  1. Click Start, type regedit in the Start programs and files box, and then press ENTER.
  2. Locate and then right-click the registry subkey HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System.
  3. Point to New, and then click DWORD Value.
  4. Type EnableLinkedConnections, and then press ENTER.
  5. Right-click EnableLinkedConnections, and then click Modify.
  6. In the Value data box, type 1, and then click OK.
  7. Exit Registry Editor, and then restart the computer.