Create Route - Chosen centerlines do not contain From or To Measures

[MichaelNigbor1]

I'm attempting to build a UPDM utility network with APR using the Gas and Pipeline Enterprise Management Solution.  I've completed the solution's task list, which included enabling APR and creating an engineering network. When I open maps, I can see the Location Referencing tab, which seems like a good sign.  Engineering Network feature class is empty, which I presume is normal at this stage. 

I want to create new a route and line. I've created a map in ArcGIS Pro that includes the published feature services and the Engineering Network.

After clicking on the "Create Route" button in the Location Referencing ribbon, I selected a single pipeline line object (a Transmission Pipe segment) which I want to be my first route.

I entered a start date, assigned line and route names then pressed the Run button. Instead of a route, I got an error that says: "Chosen centerlines do not contain From or To Measures."  as shown in this screenshot

I checked, the Pipeline Line feature class has From and To Measure fields defined, as shown below:

There isn't any data in these fields, they'll all null at the moment.

I searched GeoNet and Google, but came up empty.

What is this message trying to say? How do I fix this?  

Any help would be appreciated.

[AyanPalit · Accepted solution]

Michael Nigbor‌ The UN-APR integrated editing workflow is as follows:

1. digitize the Pipeline Line feature
2. update the From and To Measure fields based on the survey length or best guess. This will depend on the linear unit of measurement set up, say 0 - 100 (feet).
3. choose the digitized the Pipeline Line feature to create the route.
4. you will see that the From and To Measure is auto populated as it is derived from your Pipeline Line feature.

[MichaelNigbor1]

I'm working with the ESRI-supplied Naperville data, so I don't have actual survey data. To simulate this, I manually From and To values based the feature's calculated length. Now, I'm able to create routes. 

Marking as correct answer.  Thanks.