[Paraview] ParticleTracer filter

[Uriel Zajaczkovski]

Dear Paraview community,

I'm trying to use the ParticleTracer filter (PV 3.98.1) on a 3-D velocity field (computed via the calculator filter as U*iHat+V*jHat+0*kHat). 

I get this error (and PV crashes if I go ahead and apply the filter anyway):

ERROR: In /Users/kitware/Dashboards/MyTests/NightlyMaster/ParaViewSuperbuild-Release/paraview/src/paraview/VTK/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx, line 716
vtkPVCompositeDataPipeline (0x10c1143a0): Input port 1 of algorithm vtkPParticleTracer(0x10c11f320) has 0 connections but is not optional.

Any ideas of what I'm doing wrong?

Cheers,
Uriel