I am running build 5156 on macOS 13.6.1. I am refining a multi-molecule with imperfect NCS. When I tried to use "Optimize X-ray/sterochemistry" and "Optimize X-ray/ADP weight” the program aborted with an error during the first cycle. The error was: ====================== XYZ individual (reciprocal space) ====================== AttributeError I submitted a bug report via the internal bug report system. I would appreciate how to get around this problem. Should I try the previous stable version? Many thanks, Mark _____________________ Mark A. Saper, Ph.D. Visiting Professor Dept of Microbiology and Molecular Genetics Hebrew University Faculty of Medicine Associate Professor Emeritus of Biological Chemistry University of Michigan Medical School [email protected] mailto:[email protected] | +972 52 815-0480