Field Maps (ArcGIS Online) unable to view Portal layers

[AndrewRitchie_CoL]

I have create a webmap in ArcGIS Online, that reference a Map Image layer in our Portal. If I access the map from an iOS device, all layers are visible in Map Viewer.

However, if I open the map in the Field Maps App (connected to ArcGIS Online) on the same device - the Portal layers won't load. The error is:

Domain: com.esri.arcgis.runtime.error

Code: 6004

Description: JSON parser invalid start of JSON.

I expect this is because my Portal is behind a firewall, only accessible through an Azure AD Application Proxy. The browser is able to navigate this, but not Field Maps.

I'm also unable to connect Field Maps to my Portal (10.9.1 - so app should be registered automatically) - just gives a generic server connection error.

Is there going to be a way to work around this - are there extra ports or domains that need adding to the proxy?

Unfortunately I can't publish the layers to AGOL, as I need the map image layer, not a tile layer.

[GlenShepherd · Accepted solution]

Hi Andrew,

This might be something that needs to be put back to your IT team.  Are they utilising any MDM solutions to manage mobile devices within your organisation? The following resources might be of assistance when configuring Esri Mobile App access:

• ArcGIS Field Maps: Mobile device management - https://doc.arcgis.com/en/field-maps/ios/help/deploy-your-map.htm#ESRI_SECTION1_CC53DED5869D43EA8357...
• ArcGIS Field Apps and MDM Support: https://downloads.esri.com/Support/downloads/other_/ArcGIS%20Mobile%20Apps%20and%20MDM%20support%20t...
• ArcGIS Secure Mobile Implementation Patterns: https://downloads.esri.com/resources/enterprisegis/Esri%20Whitepaper%20-%20ArcGIS%20Secure%20Mobile%...
• Additional discussion in this space can also be found on Esri Community. For Example: https://community.esri.com/t5/arcgis-survey123-blog/configure-survey123-properties-in-your-mdm-with/...

However - do be aware that the 'pre-authentication' parameter for the Azure Application Proxy must currently be set to "Passthrough" in order for mobile apps (e.g. ArcGIS Field Maps, Survey123, etc...) to connect to their Portal instance.

This is currently an active enhancement request and you might like to also throw your 'kudos' behind this ArcGIS Idea, also requesting the functionality: https://community.esri.com/t5/arcgis-enterprise-ideas/azure-application-proxy-add-support-pre/idi-p/...

[AndrewRitchie_CoL]

Thanks Glen,

No MDM, but I'm following up with IT -  I'm pretty confident it will be the pre-authentication parameter, which we probably won't be able to change in our environment.

Rather than providing a proxy for Portal - which needs to remain secure - would I instead be able to create a second proxy for ./apps/fieldmaps and set the pre-authentication parameter to pass-through just for this one?

My thinking is: once the user has authenticated through the app, they would then be able view portal items through the app as well?

Otherwise, it looks like I'm just waiting on that Idea 🙂

Edit: That idea won't work - Field Maps needs to connect to /portal - not to the /apps/fieldmaps location 😞

[AndrewRitchie_CoL]

I've been able to work around the immediate issue, only by publishing to a public standalone ArcGIS Server - that I was hoping to decommission.