Scott Johnston wrote: I'm on a macbook air with Mountain Lion 10.8.5. Trying Argyll with a DTP94. I'm getting "Instrument Access Failed." Any help would be appreciated. I hope I'm doing something stupid. Hi, looks like I broke something on OS X when fixing an issue on Linux. These should fix the problem: <http://www.argyllcms.com/disptools_OSX64.tgz> Graeme Gill. ----- I'm having similar problems to Scott. I'm attempting to use Argyll with a DTP94 on Mountain Lion on a hackintosh and get similar looking errors. I installed Argyll 1.6.0 and then unzipped your attachment, replacing any existing files. I'm not sure if that was the intended use of your attachment, but regardless, it didn't appear to change anything. Here are the errors I see when I run the same command as Scott (which I admittedly don't understand, but the end error message is the same as when I attempt to use dispcalgui) bash-3.2$ sudo ./dispcal -D6 -yl -qm -gs dell20130914qmgs Found 2 screens usb_get_paths: about to look through devices: usb_check_and_add: checking vid 0x05ac, pid 0x8006, lid 0x1a000000 usb_check_and_add: 0x05ac 0x8006 not reconized usb_check_and_add: checking vid 0x05ac, pid 0x8006, lid 0x1d000000 usb_check_and_add: 0x05ac 0x8006 not reconized usb_check_and_add: checking vid 0x8087, pid 0x0020, lid 0x1a100000 usb_check_and_add: 0x8087 0x0020 not reconized usb_check_and_add: checking vid 0x8087, pid 0x0020, lid 0x1d100000 usb_check_and_add: 0x8087 0x0020 not reconized usb_check_and_add: checking vid 0x03eb, pid 0x3301, lid 0x1d150000 usb_check_and_add: 0x03eb 0x3301 not reconized usb_check_and_add: checking vid 0x05ac, pid 0x1006, lid 0x1d152000 usb_check_and_add: 0x05ac 0x1006 not reconized usb_check_and_add: checking vid 0x05ac, pid 0x0220, lid 0x1d152200 usb_check_and_add: 0x05ac 0x0220 not reconized usb_check_and_add: checking vid 0x093a, pid 0x2521, lid 0x1d152300 usb_check_and_add: 0x093a 0x2521 not reconized usb_check_and_add: checking vid 0x046d, pid 0x0802, lid 0x1a130000 usb_check_and_add: 0x046d 0x0802 not reconized usb_check_and_add: checking vid 0x0765, pid 0xd094, lid 0x1a140000 usb_check_and_add: found instrument vid 0x0765, pid 0xd094 new_inst: called with path 'usb417: (Xrite DTP94)' dtp92_init_coms: About to init USB usb_open_port: open port 'usb417: (Xrite DTP94)' succeeded usb_open_port: SetConfiguration failed with 0xe0004051 usb_open_port: SetConfiguration failed with 0xe0004051 dtp92_init_coms: set_usb_port failed ICOM err 0x20000 init_coms returned 'Communications failure' (Communications failure) new_disprd failed because init_coms failed dispcal: Error - new_disprd() failed with 'Instrument Access Failed' Any ideas?