The “Unable to set LUTs” error when trying to create a monitor profile can be caused by a combination of things. 

First and foremost, multiple monitors on all platforms (Windows and Mac) have to be set up as extended desktop...NOT mirrored or duplicate mode in order to profile.  Users will likely encounter a variety of errors attempting to profile multiple displays in mirrored or duplicate mode.

Next, check to see if the computer display’s menu has “DDC” or “DDC/CI” enabled or turned on.  If so, disable it or turn it off in the display’s menu.  Furthermore, we would recommend turning off “ADC” (Automatic Display Calibration) if this error appears when profiling.  Follow these instructions to turn “ADC” off:

1. In the “Measurement” step, select the “Adjust brightness, contrast, and RGB gains manually”. This will unselect "Automatic Display Control (ADC)"
2. Uncheck the contrast or RGB options if those controls are not manually adjustable on the monitor.  DO NOT unselect the option to adjust brightness manually…this must remain selected.
3. Click “Next” to save these settings and begin the profiling process.
4. When saving the profile, save it with a unique name (i.e., add the month and year before the extension). Overwriting a previous profile with the same name can often cause a LUT error.

There are some PC video cards that do not support LUTs (Look Up Tables).  If the aforementioned settings changes do not allow the profile to be created, consider the web article that includes a small test utility at the following link: 

http://www.xrite.com/product_overview.aspx?ID=1513&Action=support&SupportID=2933