Hi Tony,
I am not sure if you are referring to the block replacement suggestion, or the "failed" message.
If you are referring to the block replacement suggestion, this is just suggesting you replace your normal "lookup table" block with the "n-D lookup table" block. The "n-D lookup table" block is compatible with all dimensions of lookup tables, and could improve simulation speed. This is not a required change.
If you are referring to the "failed" message - it appears that this check is only marked as a failure because none of the signals in your model are configured for logging. When a signal is logged, its value throughout the simulation is saved, allowing you to go back and analyze the data post-simulation. You can read more about enabling signal logging in your model on this documentation page.
