The option to show where route measures don't have any value (NaN) was available in ArcMap by going to Layer Properties-->Routes. I can't find this option in ArcGIS Pro. I'm trying to find a way to either visualize this or generate a list of records with missing measurement values.
Can you just go to Select by Attributes and then create an exp for field is NULL?
That functionality wasn't brought over from ArcMap to ArcGIS Pro. It's an equivalency issue. There is an idea for it somewhere but I can't find it right now.
What kind of geodatabase (file, mobile, or enterprise) and what kind of enterprise database (Oracle, SQL Server, PostgreSQL)? If it's an enterprise geodatabase, then you might be able to query for it using SQL. What kind of spatial type? ST_GEOMETRY? Oracle's SDO_GEOMETRY?
Or maybe someone can come up with a Python solution or an attribute rule that would put a flag in a field.
@Laura The linear referencing M-value is a component of the SHAPE field. It's a type of coordinate, just like X, Y, or Z. Each vertex in an M-enabled FC has a X, Y, and M value, so it can be tricky to query the M values because there are multiple per line.
Is it a line feature class?
Do you need to find lines that have ANY vertices with missing M values? Or would it be good enough to find lines where the start vertex or end vertex are missing the M value?
Calculate Geometry has options for getting the M value of the start and end of lines: