I eventually managed to get AutoSegmentator working with 3D Slicer using the sample CT dataset. No error is generated after segmentation and I can view 3d and each of the 22 segments. Using Segmentation module I tried to export stl files for all 22 organ segmentation. The generated stl files are all 1k in size and can not be displayed using any of the popular 3d model viewer such as MeshMixer and Ultimaker Cura. Not sure if it is possible to upload the stl file here.