Geometry is not M-aware issue with Polygon Neighbors

[TatyanaDeryugina1]

I'm trying to calculate which CA zip codes border each other using Polygon Neighbors. I keep getting the error that the "Geometry is not M-aware". Initially, the dataset did not have M-values. I added them using "Feature Class to Shapefile" and turning on M-values in the Environment options. I also repaired the Geometry. I tried running Polygon Neighbors with disabled M-values in the Environment options. Same error every time. I don't know what else to do.

The dataset to which I added M-values is attached. FYI, I'm using ArcGIS 10.4

[DanPatterson_Retired]

the shapefile has issues, but it isn't the shapefile itself.  You need to add it to a geodatabase as suggested in this thread

Geometry is not M-aware

What is a file geodatabase?—Help | ArcGIS for Desktop

so you can try converting the shapefile to a filegeodatabase, making it m-aware using

Feature Class to Feature Class—Help | ArcGIS for Desktop

then try to see if the tool works.

According to the reference thread it solved their problem

[TatyanaDeryugina1]

Thank you for the suggestion, Dan! Unfortunately, that did not work for me. I created a geodatabase, converted the shapefile to a geodatabase using "Feature Class to Geodatabase", then tried running the Polygon Neighbors tool on the Geodatabase file. The good news is that it didn't give me a geometry error; but it still gave an error (a pretty uninformative one, basically that it failed to execute). I also tried the "Feature Class to Feature Class" conversion after creating a Geodatabase, but that gave a geometry warning as well.

Fortunately, I found a workaround. I just converted the polygons to lines and checked the box that reports bordering FIDs, which is all I really needed.