Thank you guys, now the new version is running!

To Torsten:

However, I still got the same error message... My images are fly ventral nerve cords, and they are converted from lsm into PIC files.

My commands were:

make_initial_xform --principle-axes VNCIS1.PIC tilted01.PIC initial.xform

registration --initial initial.xform -dofs 6, 12 --auto-multi-levles 4 -o affine.xform VNCIS1.PIC tilted01.PIC

warp -o warp.xform --grid-spacing 40 --refine 3 --energy-weight 1e-1 --initial affine.xform VNCIS1.PIC tilted01.PIC

reformatx -o reformat.nii --floating tilted01.PIC VNCIS1.PIC warp.xform

The image files are ~100MB, do you have a preferred way to share them?

Xiaojing