MR error when displacing a cube

[sonne]

I'm trying to displace a simple cube, but I keep getting the following error message:

Message: GAPD 0.0 error 091079: too small triangles when displacing
polygons

Any ideas??

These are my settings:

Spatial : 3.0
Units : Pixel Length

SoftImage 3.9.2
MR 2.1
PIII 2x850 mhz
512 MB ram

Thanx,

Peter