Hi, I think there's a slight glitch in Polder which I am currently testing. The program works fine. However, the log file shows the full phil parameter for the selection string solvent_exclusion_mask_selection whereas the json file does not. As an example I have a log file: ------------------------------------------------------------------------------- data_manager { miller_array { file = "../74343_262277_1_1.mtz" } default_miller_array = "../74343_262277_1_1.mtz" model { file = "../74343_262277_4_1+ligands.pdb" } default_model = "../74343_262277_4_1+ligands.pdb" } polder { box_buffer = 5 } solvent_exclusion_mask_selection = ( chain Y and ( ( resseq 1 and name C1 \ ) or ( resseq 1 and name C2 ) or ( \ resseq 1 and name C3 ) or ( resseq 1 and \ name C4 ) or ( resseq 1 and name C5 ) or \ ( resseq 1 and name N6 ) or ( resseq 1 \ and name C7 ) or ( resseq 1 and name H8 \ ) or ( resseq 1 and name H9 ) or ( \ resseq 1 and name H10 ) or ( resseq 1 \ and name H11 ) )) mask_output = True output { overwrite = True } But in the polder_modified.eff.json file it reads: ------------------------------------------------------------------------------- { "data-manager-miller-array-file": "../74343_262277_1_1.mtz", "data-manager-default-miller-array": "../74343_262277_1_1.mtz", "data-manager-model-file": "../74343_262277_4_1+ligands.pdb", "data-manager-default-model": "../74343_262277_4_1+ligands.pdb", "polder-box-buffer": 5, "solvent-exclusion-mask-selection": "(", "mask-output": true, "output-overwrite": true } Regards, Rob