Using Map Viewer how do I identify the source of a layer in an existing Web Map object?

[JeffSilberberg]

I have inherited some Web Maps that are actually rolled into Experience Builder Apps. 

When I open the Web Map in Map Viewer, many of the Layers have a " An error occurred loading this layer."  Message under them.   

My question is: how do I determine the Source of the Layer so that I can try to identify the issue?  Security, Corrupt Object, Missing Object, Firewall issue. 

I have tried using the Debug Tools, Console View, and Filtering to Errors only, but honestly, there is so much noise in this Web Map that I can't really make heads or tails from the error data. 

Failed to load resource: net::ERR_NAME_NOT_RESOLVED" 

[@arcgis/core/views/support/LayerViewManager] ..........

Failed to create layerview for layer title:'Trails', id:PTrails_1648' of type 'feature'. Object".

[CodyPatterson · Accepted solution]

Hey @JeffSilberberg 

Would you have administrator permissions on this organzation? If not, you may have permission issues blocking you from accessing the underlying layers initially.

There's a chance that using the browser developer tools will let you see the URL that is being requested by the map, which would point you in the right direction to find the actual feature layer. The ERR_NAME_NOT_RESOLVED would be something I would look more into as it may link to the issue, the console should also throw errors with the same "An error occurred loading this layer." message too.

I've also seen it may be possible to download the map JSON using the REST endpoint on ArcGIS Online or the ArcGIS Assistant to download the JSON as well, I'd just go to https://assistant.esri-ps.com/signin and try it out, I've seen this online and haven't tested it myself though.

Let me know if there's any HTTP codes or anything on the request, some may give a little more insight like 403 being credentials or something!

Cody

[JeffSilberberg]

@CodyPatterson 

Cody, Thank you very much for replying. 

* Yes, I am logging in a profile that has both Adminsitartor & Creator authority. 

* The browser developer tools are, as usual, very helpful, but the Console is so clogged with Error-level messages that it's really impossible to determine what is going on in this case. 

* ArcGIS Assistant is what helped me identify the issue.  Had not seen this tool before, or if I had, I just forgot about it - I could not get the View Item to give me any useful data, so I used View JSON.  Then copied the JSON to a local file and used GREP to find the various layer definitions.   Could not find a Download button, but didn't really need one as CTL+A worked just as well. 

* With this data, I was able to determine that someone had updated the Webmap object with Enterprise Layers, versus the ArcGIS Online layers they should have been using.  

Thanks again -- 

[CodyPatterson]

Hey @JeffSilberberg 

Great to hear! Glad that the Assistant was able to get you going, I've had that same issue using the wrong layers and it was quite the heavy issue to find at first!

Cody