Hi, I am using the ChimeraX modeller comparative command in both ChimeraX 1.7 and ChimeraX 1.11.1. The command executes successfully in both versions, but the results are significantly different. The model generated with ChimeraX 1.7 appears correct, whereas the model generated with ChimeraX 1.11.1 appears incorrect. One notable difference is the GA341 "correlation" score: it is close to 1.0 (high confidence) in ChimeraX 1.7, but close to 0.0 (very low confidence) in ChimeraX 1.11.1. The test data is: Sequence: UniProt P69905 (human hemoglobin) Template structure: PDB 2DHB (horse hemoglobin) Alignment: attached file The exact command used was generated using chimerax GUI: modeller comparative aligned_1.fasta:2 numModels 5 fast false multichain true hetPreserve false hydrogens false waterPreserve false Has anyone observed similar differences between ChimeraX versions, or can suggest a way to obtain consistent Modeller results in the latest releases of ChimeraX? Thanks in advance for any help. Roberto