GEE error - an error that occurs when using NLCD data for land use data sampling

Error introduction:

I'm trying to sample LULC points from NLCD and MOIDS, and I've written a function to do this over a period of time. However, filtering the NLCD dataset results in errors. It only happens inside functions. I did this for a year and it worked great. Can anyone help me?

There are only two years of data in GEE, so the middle years are not available, so only two years can be sampled.

mistake:

LULC

ImageCollection (Error)

Image.select: Parameter 'input' is required.

Sample

FeatureCollection (Error)

Image.select: Parameter 'input' is required.

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MCD12Q1: Layer error: Image.select: Pa