Problem with RAM upgrade on Precision 3660 Tower

Hi,

I have a problem with upgrading RAM to an 3660 Tower (12700k, 16GB)

I checked crucial website for a compatible kit and found CT2K16G48C40U5 (2x16GB modules)

I bought it and installed the kit (I took out the Dell modules) and receive a orange/white blinking LED. It's blinking 2x orange and 5x white- which means "incorrect memory installed".

How can I fix it? Crucial says the RAM is compatible.

(have BIOS 1.2.38 installed)