Unable to process displacement of the object(s) due to extreme number of generated vertices.

This error message appears after reaching the limit of vertices generated by displacement. Corona can handle detailed displacement even at high resolutions, however, as everything else, it can fail when using extreme values. 

Solutions:

• Lower the overall displacement quality. You can do this in Render Setup > Performance > Displacement.  Higher displacement size values result in lower quality both when using the screen size and the world size. Generally, it is recommended to use screen-size displacement as it requires less RAM and is more efficient. 
• Limit the visibility of the displaced objects on screen (a small area with displacement will generate less vertices than a very large area covering the whole screen). 
• Lower the resolution of the rendered image to generate less displacement vertices. This only applies to screen-size displacement and won't work in case of world-size displacement. 
• Use bump instead of displacement. This is only possible if the geometric detail generated by displacement is not required. 
• Use other features instead of displacement to achieve the desired effect (e.g. Corona Pattern). 
  
  • Corona Pattern Modifier - 3ds Max
  • Displacement, Scatter, and Pattern usage differences

See also: 

• I am getting a sudden rise in RAM usage!
• Stopping render due to not enough system memory to process displacement
• My displacement has huge spikes or is invisible!