If a ColorMunki Display user is receiving an "ColorMunki Display not connected" message when attempting to measure the color patches or ambient light, try the following to establish connection to the device:

1. First...unplug the ColorMunki Display, reboot the computer, plug in the ColorMunki Display after the computer has completely restarted, and then open the ColorMunki Display software application to test.
2. Make sure that the current version of ColorMunki Display 1.1.1 on PC:  http://www.xrite.com/colormunki-display/support/d1457 and ColorMunki Display 1.1.0 on Mac: http://www.xrite.com/colormunki-display/support/d1381
3. If the current version is installed and it still will not connect, close the ColorMunki Display program, unplug the measurement device from the USB port, plug into another USB port (preferably a rear port on a tower…never into a keyboard, monitor, USB extension, or unpowered USB hub), and reopen the ColorMunki Display program to test.  The use of a powered USB hub has sometimes resolved this issue due to unreliable USB power with some computers.
4. If step #2 fails to correct the issue, close the program, unplug the measurement device from the USB, reboot the computer, plug in the USB, and open ColorMunki Display to test.
5. If the device still fails to connect, download and install the most current version of X-Rite Device Services (XRD) in the "Software Downloads" section of the XRD support page at the following link: http://www.xrite.com/product_overview.aspx?Action=support&ID=1509
6. Anti-virus and/or firewall software can sometimes prevent devices from properly connecting to a program.  Please see the additional information at the bottom of this page entitled "Connection Issue On PC With Microsoft Security Essentials", "Thunderbolt Display Causes USB Problem?", and "Instrument recognition issue could be caused by Virus Protection Tools" for examples of how a user might eliminate this variable.  

If all suggestions above fail to correct the issue, contact X-Rite Customer Service.