Thanks Hal and Andreas. After adding #define DEBUG as the first enry in the file and changed the line #undef DEBUG to #undef DEBUG2 (I discovered this by an accident) I have plenty of debug info. ltg@buntu:~/src/Argyll_V1.0.0$./spectro/dispwin -vv -I ~/i1.icc About to open dispwin object on the display About to install '/home/ltg/i1.icc' as display's default profile ucmm_install_monitor_profile called with profile '/home/ltg/i1.icc', edid 0x5b8ef353, disp ':0.0' verified profile OK config file = '/home/ltg/.config/color.jcnf' data file = '/home/ltg/.local/share/color/icc/devices/display/i1.icc' profile copied OK Searching for EDID = '0x00FFFFFFFFFFFF004C2DAA0039315947280D01036C261F782A9AE6A2584B9923144F54BFEF008180818F314001010101010101010101302A009851002A4030701300782D1100001E000000FD00384B1E510E000A202020202020000000FC0053796E634D61737465720A2020000000FF00484A47573930383431300A202000E2' Adding a new record 1 jcnf write to '/home/ltg/.config/color.jcnf' failed with error 11 Dispwin: Error - Failed to install profile '/home/ltg/i1.icc'! Please tell me if you need more info. Regards Lars Tore