Is this server came with 12 CPU and without Riser 2 or you installed 2nd CPU later. 2 CPU configuration need Riser 2 to be installed. This error is coming as this is not a supported configuration.  You can install Riser 2 to remove this error. Below link have a list of supported riser configurations for R650xs [URL]  You also have an option to hide this error message in BIOS -> iDRAC Settings page. Once disabled this error message will not be shown during POST.
Hi, I have a problem with dell R650xs, the server has 2 processors installed, but the error HWC8010: the system configuration check operation resulted in the following issue: config missing: Riser 2 Why does this error occur? [IMAGE]
R650xs Missing Riser 2