I have a protein with PDB (1ZK4), it obtains NADP as ligand in its structure when I tried to dock it, I faced error while creating the PDBQT file for this protein in AutoDock :Error: "Non-integral charge on residues" and the second error during grid run: Error:"Found an H-Bonding atom with three bonded atoms, atom serial 1903". When I removed NADP from my receptor protein I got the proper docking results. Can anyone explain why it was so?