Error in pdb4dna example when changing PDB file

Geometry, Fields and Transportation
1

Hello everyone,
I have successfully tested the pdb4dna example with default PDB file: 1ZBB.pdb, however when I changed this file by another, I got the following error:

Barycenter list is null!!!

0 entries: Number of SSB
0 entries: Number of DSB

Any advise .

Thank you and regards.