I'm sorry, but I have to chime in here -- You guys have to do a better job in making ArcServer layers accessible in a desktop environment. In my experience, your technology has moved in backwards direction in recent years.
Hi Joe, thanks for your response. Your error message is identifying the issue for you. These parameters are not enough "where=1=1&outFields=*&f=pjson". I put them in there as an example of the key parameters you need to change. You may still need all of the other parameters, but you can just use the default values for those parameters. Here's an example using one of Esri's sample services:
1) Open https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3/query in your browser.
2) In the Where parameter, type 1=1
3) In the Outfields parameter, type *
4) In the Format parameter, use JSON
5) Click Query (GET) and when the response comes back, look at the request parameters in the URL in your browser's address bar, i.e. https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3/query?where=1%3D1&tex...
You may need those parameters in your request, even though the parameters are empty. You may not need all of the parameters. You will need to check by trial and error.
However, in saying that, this URL works fine without all of the parameters: https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3/query?where=1=1&outFi...
It is possible that earlier versions of ArcGIS Server may require the full parameters but maybe later versions don't. You can check the version via the REST Services Directory endpoint for the map server, e.g. https://sampleserver6.arcgisonline.com/arcgis/rest/services
Let me know if it is still not working for you.