I've been trying to get coot running on my MacBook Pro after upgrading to OS X El Capitan (10.11.6). I have installed as part of ccp4, Phenix (1.9-1692) or standalone (0.8.8) (As provided by the Scott lab at UCSC). I'm also running X11 (2.7.11). It seems to be fine, unless I have my big Mac Cinema HD Display connected (via USB). When the big monitor is plugged in, all coot windows just disappear. They reappear on the notebook screen if I disconnect the remote monitor.
Never had this problem with the same hardware and older versions of the Mac OS, an have not had problems with windows from other software, either - just coot. Is this a problem others have observed and/or dealt with? --Barry Finzel