I tried your commands on dsets here, and the output *netcc files looked fine.
I don't you if perhaps there is a bad character in that D*txt file? You can check with:
file_tool -show_bad_all -infiles DKT.txt
Sidenote: this should not be included in the 3dNetCorr command:
sub.niml.lt
That option does not take an argument:
-ts_wb_strlabel :by default, '-ts_wb_{corr,Z}' output files are named
using the int number of a given ROI, such as:
WB_Z_ROI_001+orig.
with this option, one can replace the int (such as
'001') with the string label (such as 'L-thalamus')
*if* one has a labeltable attached to the file.
I don't see that affecting the 3dNetCorr stuff, though.
--pt