R720 with 12 X 8GB RAM not working

Hi, we buy some RAM and would like to upgrade the R720 server, but after I plug the RAM to the R720 server, it showed:

Fatal Error! No memory detected!

DIMMs A1, A5 and A9 exceed maximum total number of ranks supported.

DIMMs A2, A6, and A10 exceed maximum total number of ranks supported.

DIMMs A3, A7, and A11 exceed maximum total number of ranks supported.

DIMMs A4, A8, and A12 exceed maximum total number of ranks supported.

Please remove dimes and populate in a supported configuration

Does the R720 not support 12 X 8GB = 96GB?