Summary
ArcGIS Event Editor is a map-centric web app that supports linear referenced event data editing. ArcGIS Event editor can be configured with ArcGIS Enterprise. It requires a Location Referencing license.
Even after publishing a web map layer with linear referencing system (LRS) capability, while configuring ArcGIS Event Editor an error is returned, indicating that "No linear referencing system was detected in the map description", shown in the image below.

Procedure
- Install the ArcGIS Location Referencing Event Editor Web App setup file from My Esri.
- Make sure to use a compatible version of ArcGIS Pro and ArcGIS Enterprise with the required license.
- In ArcGIS Pro, publish the web map layer with linear referencing and version management.
- Navigate to the location referencing directories "C:\Program Files\Common Files\ArcGIS\LocationReferencing".
- Copy the EventEditor folder to "C:\inetpub\wwwroot" Navigate to IIS manager, and check the EventEditor folder.
- Specification of the IP Address or hostname is not required, as it will work with "All Unassigned" in Site Bindings (IIS Manager), as shown in the next image.

- Navigate to "C:\inetpub\wwwroot\EventEditor11.0\config.json"
- Modify the below properties.
- webmap: Open Map image layer from content of your ArcGIS Portal. save it as web map and copy web map ID from URL.
- portalAppId: Create a a Web Mapping Application from the portal. Put the Data source URL and redirect URL as: https://domainname/EventEditor11.0. Select ready to use in Purpose and Other in API. Generate the portalAppID by registering the app and copy/paste in the config.json.
- Portal URL: Copy/paste the portal URL in config.json
- Save the config.json.
- Open the following URL in a browser: https://domainname/EventEditor11.0.
- Allow ArcGIS Event Editor to access ArcGIS Enterprise by clicking Allow. ArcGIS Event Editor is successfully configured.

Note:
It is not required to make any changes to any other properties of the config.json for configuration of Event Editor.
Without linear referencing and version management, configuration of Event Editor is not possible.