DRAM / MEMOK Red Led stays lit

[leobotez.lb]

Hello,
I have this pc for 1 year and worked perfectly. But today I pulled out one RAM stick, worked perfectly again. And then I've put again the RAMS but in not the same order. And now, I have the motherboard ASUS Z170-A and on it, is a red light,that stays lit. (MEMok / DRAM button)

What should I do now?

 

[rocktalkrock]

The RAM should be located in DIMM_A2 and DIMM_B2.