UKF exit abnormally

Hello, I’m using ubuntu 20.04 , i ran following command with error:
./Slicer --launch UKFTractography --dwiFile /home/inspire_lab/Downloads/IXI-DATA-nrrd/combine_conform_IXI034-HH-1260.nrrd --maskFile /home/inspire_lab/Downloads/IXI-DATA-brain_mask/combine_conform_IXI034-HH-1260_brain_mask.nrrd --tracts /home/inspire_lab/Downloads/combine_conform_IXI034-HH-1260_tract.vtk --recordFA --recordTrace
Using the 2T simple model. Setting the default parameters accordingly:
“*”: set by user
“-”: default setting

  • stoppingFA: 0.15
  • seedingThreshold: 0.18
  • Qm: 0.001
  • Ql: 50
  • Rs: 0.02
  • stepLength: 0.3
  • recordLength: 0.9
  • stoppingThreshold: 0.1
  • seedsPerVoxel: 1
    Found 20 cores on your system.
    Running tractography with 20 thread(s).
    DWMRI_b-value 1000
    Number of non-zero gradients: 15
    Number of zero gradients: 1
    Permuting the axis order to: 3 0 1 2
    Resizing the data to: 15 256 256 256
    Computing the baseline image
    Dividing the signal by baseline image
    Converting the world coordinate system to RAS
    Data normalization finished!

Using 2-tensor simple model.
Branching disabled

Using unconstrained filter
error: [slicer.org/Extensions-32438/UKFTractography/lib/Slicer-5.6/cli-modules/./UKFTractography] exit abnormally - Report the problem.
what exactly is the problem?