What is wrong with this PDB script line?

HADDOCK
,
2

Here is a website that tells you how a PDB file should be formatted: https://cupnet.net/pdb-format/.

  • Make sure everything is ok column-wise.
  • Also I am not sure of the meaning of the CARA at the end of the line.
  • Finally, you could try to replace HETATM to ATOM .