Area-51 R2, RAM upgrade help

I have an Alienware 51 R2 Motherboard MS-7862 with an intel i7-6850k processor and stock 16 GB quad channel DDR4 memory at 2133 Mhz.  I wanted to upgrade the existing memory to 32 GB and operating at a higher frequency 3200 Mhz.  My understanding is that the board will support higher RAM capacity and speed, so I bought a set of Corsair Dominator DDR4 32GB at 3200 Mhz.  After I installed it, I enabled the XMP and set the RAM speed to 3200 Mhz but the system wouldn't boot.  So I tried to set everything to Auto and disable the XMP, however I keep getting a message that the "System Memory capacity has changed" and prompted me to either continue as it is or go into BIOS to change the setting.

Anyone know what is the issue here?  And know what I need to do to increase my RAM capacity and set the RAM speed at a higher speed?

Thanks.