Hi Almudena, Can you possibly say what version of Phenix you are using: phenix.version and then the columns in your mtz file: phenix.mtz.dump my_mtz_that_fails.mtz and the inputs you used for autosol and phaser (you can send the top part of the log files that should have this information). Can you also try this little test for resolve model building (that is where the "cannot read segment library" comes from): phenix_regression.wizards.test_command_line_build test_autobuild_quick That would help for diagnosing the problems. All the best, Tom T Hi everyone, I am facing some troubles with PHASER and with AutoSol (things that did not happen earlier to me). I am working with anomalous data and the first thing I do is to run HySS in order to find the heavy atoms sites. Once this is done I have two options: run PHASER or run AutoSol. Phaser gives the following error message: ERROR setting up data inputs (FATAL RUNTIME) Can not find MTZ column "F_SAD_SAD(+)" Instead Autosol gives the following: ERROR sorry can not read segment library Could anyone help me out here? Thank you very much in advance. Best, Almudena -- Almudena Ponce-Salvatierra Macromolecular crystallography and Nucleic acid chemistry Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany