To get the Vray RT Activeshade renderer to display displacement maps you’ve assigned to objects with the Vray displacement modifier make sure the Displacement box is ticked in Render Setup under Active Shade/V-ray RT as shown.
Turn up the Amount on the Vray Displacement modifier to an extreme value to make sure the effect is very obvious.
If you’re getting error 0x0000273f on one of your Backburner servers try this Microsoft Fixit on that particular system’s Windows installation which might be corrupted say by a recent power cut or forced shutdown: http://www.microsoftfixit.net/windows-error-0x0000273f/