Question MOBO Debug LED indicates DRAM isn't detected or has failed, not sure what is the root cause.

Jul 24, 2019
PCPartPicker Part List:

CPU: AMD Ryzen 5 2600X 3.6 GHz 6-Core Processor (£149.93 @ More Computers)
Motherboard: MSI B450M GAMING PLUS Micro ATX AM4 Motherboard (£71.99 @ CCL Computers)
Memory: Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory (£69.97 @ Amazon UK)
Storage: Crucial MX500 250 GB 2.5" Solid State Drive (£37.38 @ Aria PC)
Storage: Seagate BarraCuda 1 TB 3.5" 7200RPM Internal Hard Drive (£34.98 @ Aria PC)
Video Card: NVIDIA GeForce GTX 1080 8 GB Founders Edition Video Card
Case: Cooler Master MasterBox Q300L MicroATX Mini Tower Case (£39.99 @ PC World)
Power Supply: SeaSonic S12II 620 W 80+ Bronze Certified ATX Power Supply (£55.47 @ Amazon UK)
Monitor: AOC E2470SWH 23.6" 1920x1080 60 Hz Monitor (£91.20 @ CCL Computers)
Total: £550.91
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-07-24 19:44 BST+0100

I just finished building my new PC but when I start it up, my MOBO's debug LED for DRAM lights up, is the problem with compatibility or something else, would rather find out where the problem is before replacing anything only to find out the problem was elsewhere.