Hi all, There seems to be an issue with XQuartz 2.7.9 on OS X when trying to render an OpenGL window (e.g. Coot, PyMOL, Phenix GLViewer) over SSH using X forwarding (i.e. ssh -Y). You will get an error that looks like X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 150 (GLX) Minor opcode of failed request: 3 (X_GLXCreateContext) It seems like indirect rendering of a GLX context does not work properly on 2.7.9. Downgrading to XQuartz 2.7.8 works for me. -- Billy K. Poon Research Scientist, Molecular Biophysics and Integrated Bioimaging Lawrence Berkeley National Laboratory 1 Cyclotron Road, M/S 33R0345 Berkeley, CA 94720 Tel: (510) 486-5709 Fax: (510) 486-5909 Web: https://phenix-online.org