If a display profile produces poor results (color cast, low contrast, high contrast, low luminance, etc...), try reprofiling after making sure to check the following:

• Connect the measurement device to a properly powered USB port.  Typically, a tower will have rear ports that more reliably and consistently deliver the required power to the device.
• Avoid using USB ports on keyboards and monitors.  Also avoid unpowered USB hubs as well as USB extensions.
• An acceptable extension is the use of a powered USB hub.  Some laptop computers will require a powered USB hub to deliver the necessary power.
• PLACE THE MEASUREMENT DEVICE FLUSH ON THE SCREEN WHEN PROFILING!  This will more easily be accomplished tipping the display back and carefully place the device on the screen while viewing from the side.  An instrument that is not flush on the screen’s surface will result in bad measurement data and then poor results when using the profile.  Do not push on the device while measuring as pressure can change color on LCD screens.
• Consider turning off all anti-virus and/or firewall software when profiling.
• Laptops must have the power supply connected when profiling.
• Go to System Preferences > Displays and uncheck “Automatically adjust brightness” if it is available.

If the aforementioned suggestions fail to correct the issue, please do the following in exactly this order:

1. Go to System Preferences > Accessibility and select the “Display” option on the left.  All check boxes should be unchecked except "Reduce Transparency"...that should be checked.  Make sure that the “Display Contrast” slider is set all the way to the left at “Normal”.
2. Now go to the Applications folder and right-click (or control-click) on the i1Profiler application icon and click on “Show Package Contents”
3. Navigate to Contents > MacOS > Profiles and then copy and paste the “XRite_LinearProfile.icc” profile to the Mac HD\Library\ColorSync\Profiles folder.  Close Finder.
4. Open “Displays” in System Preferences and select the “Color” tab.  Click on the profile named “DisplayProfile_Linear.icc” to reset your display’s RGB channels to a linear fashion.  The onscreen color should change and will likely look bad.
5. Close Displays and System Preferences.
6. Connect the i1Display Pro and open the i1Profiler software application.

Profile the display using this workflow:

Turn off “ADC” (Automatic Display Calibration) when profiling in the Advanced Mode of i1Profiler.  Automatic Display Control (ADC) can sometimes produce unsatisfactory results.  Follow these instructions to turn “ADC” off:

1. Typically, users should select a white point of “D65”, a luminance setting of “120”, and “Native” for contrast ratio.  Select “White LED” for your Technology Type if it is an Apple display manufactured after 2009. If this is the new 4K 21.5" or 5K 27" Retina iMac manufactured in Late 2015 or later, select "GB-LED (RG Phosphor)" for the Technology Type.  
2. In the “Measurement” step, select the “Adjust brightness, contrast, and RGB gains manually”. This will unselect "Automatic Display Control (ADC)"  
3. Uncheck the contrast and RGB options as those controls are not manually adjustable on an Apple monitor.  DO NOT unselect the option to adjust brightness manually…this must remain selected. When adjusting brightness on an Apple display (iMac, MacBook, or Apple displays), you may need to open System Preferences > Displays to fine tune the brightness to more closely match the target.
4. Click “Next” to save these settings and begin the profiling process.
5. Create a new display profile.  When you create and save the profile, save it with a unique name.  Perhaps you can add the month and year to the name (i.e., iMac_Feb2014.icc).  You will need to retain the “.icc” extension.