Hi there, i've encounter the error below when running dwi2response. It appears that this error only occurs on 1 out of 91 of my subjects. If its helpful, i've uploaded beddytensors.mif here https://drive.google.com/file/d/1omAdS-2td2PwVZjIPEVlmEB4FWdQvYjB/view?usp=sharing

junhong@junhong-Precision-5820-Tower:/bcs/junhong/MAP/data/017/time1/DTImrt2$ dwi2response dhollander beddytensors.mif wm_response.txt gm_response.txt csf_response.txt -nthreads 20 -force
dwi2response:
dwi2response: Note that this script makes use of commands / algorithms that have relevant articles for citation. Please consult the help page (-help option) for more information.
dwi2response:
dwi2response: Generated scratch directory: /bcs/junhong/MAP/data/017/time1/DTImrt2/dwi2response-tmp-KZJOBX/
dwi2response: Importing DWI data (/bcs/junhong/MAP/data/017/time1/DTImrt2/beddytensors.mif)...
dwi2response: Changing to scratch directory (/bcs/junhong/MAP/data/017/time1/DTImrt2/dwi2response-tmp-KZJOBX/)
dwi2response: Computing brain mask (dwi2mask)...
dwi2response: -------
dwi2response: 3 unique b-value(s) detected: 0,1000,3000 with 14,60,60 volumes
dwi2response: -------
dwi2response: Preparation:
dwi2response: * Eroding brain mask by 3 pass(es)...
dwi2response: [ mask: 49228 -> 32396 ]
dwi2response: * Computing signal decay metric (SDM):
dwi2response: * b=0...
dwi2response: * b=1000...
dwi2response: * b=3000...
dwi2response: * Removing erroneous voxels from mask and correcting SDM...
dwi2response: [ mask: 32396 -> 32393 ]
dwi2response: -------
dwi2response: Crude segmentation:
dwi2response: * Crude WM versus GM-CSF separation (at FA=0.2)...
dwi2response: [ 32393 -> 17770 (WM) & 14623 (GM-CSF) ]
dwi2response: * Crude GM versus CSF separation...
dwi2response: [ 14623 -> 10032 (GM) & 4591 (CSF) ]
dwi2response: -------
dwi2response: Refined segmentation:
dwi2response: * Refining WM...
dwi2response: [ WM: 17770 -> 16257 ]
dwi2response: * Refining GM...
dwi2response: [ GM: 10032 -> 5785 ]
dwi2response: * Refining CSF...

dwi2response: [ERROR] Unhandled Python exception:
dwi2response: [ERROR] ValueError: could not convert string to float: N/A
dwi2response: [ERROR] Traceback:
dwi2response: [ERROR] /home/junhong/mrt/mrtrix3/bin/dwi2response:118 (in execute())
dwi2response: [ERROR] alg.execute()
dwi2response: [ERROR] /home/junhong/mrt/mrtrix3/lib/mrtrix3/dwi2response/dhollander.py:196 (in execute())
dwi2response: [ERROR] statrefcsfcount = image.statistics('refined_csf.mif', mask='refined_csf.mif').count
dwi2response: [ERROR] /home/junhong/mrt/mrtrix3/lib/mrtrix3/image.py:252 (in statistics())
dwi2response: [ERROR] result.append(ImageStatistics(float(line[0]), float(line[1]), float(line[2]), float(line[3]), float(line[4]), float(line[5]), int(line[6])))