Does anyone know what the error "floating point error" is suppoed to be?? I am a beginner and am testing with a VOF model of free surface (air and water) with a UDF of a sine wave, and turbulence.

do you get this error while initializing the computational domain? if so, check the turbulence parameter you set. reduce the turbulence intensity to less that one for first, say 50 iterations.

if you still get the error, initialize the domain with nothing to 'Compute from...' Then click 'init'. Again select the surface from which you want to compute the initial values & iterate. this should work.