Unsupported 1GB or 2GB Density Error for Intel® NUC Kits NUC6CAYS and NUC6CAYH

What are you seeing? 

The following error displays when starting the Intel® NUC:

Unsupported 1Gb / 2Gb density SODIMM(s) detected on SODIMM Slot 2. System instability or data loss possible. Replace with SODIMMs with 4Gb or higher density. Continue (Y/N).

Why are you seeing it?

The memory modules you've installed use either 1 or 2 Gbit (gigabit) technology, also known as SDRAM density. The processors on these Intel NUC models support only DDR3L memory modules with 4 Gbit or 8 Gbit technology.

Memory modules using 1 Gb or 2 Gb density aren't supported, due to the possibility of system instability. This error message can't be disabled.

How to fix it.

Install SODIMMs with a density of either 4 Gbit or 8 Gbit. See the tables below for diagrams of compatible and incompatible memory configurations.

Click  on the topic for details:

Compatible memory configurations

Compatible	Capacity: 2 GB Total number of chips: 4 Density: 4 Gbit
	Capacity: 4 GB Total number of chips: 8 Density: 4 Gbit
	Capacity: 8 GB Total number of chips: 16 Density: 4 Gbit
	Capacity: 4 GB Total number of chips: 4 Density: 8 Gbit
	Capacity: 8 GB Total number of chips: 8 Density: 8 Gbit

Incompatible memory configurations

Incompatible	Capacity: 1 GB Total number of chips: 8 Density: 1 Gbit
	Capacity: 2 GB Total number of chips: 8 Density: 2 Gbit
	Capacity: 2 GB Total number of chips: 16 Density: 1 Gbit
	Capacity: 4 GB Total number of chips: 16 Density: 2 Gbit