On a few motherboards, the M.2 heatsink on the south side of the CPU socket may interfere with the Liquid Freezer III.
We will be happy to provide you with a suitable M.2 heatsink. Please, contactARCTIC Support to ask for a free of charge replacement. Please enclose the invoice of your motherboard with your request as justification.
You can either replace the M.2 heatsink with a thinner heatsink or remove it completely.
Go to Installation Manual