The lack of support for JSON files in D365 is a pain in the ass. Certainly if you want to share the same datafile between JScript & Plugin. The know workaround is to set JSON content in a web resource of type XML. It would be nice if we could link a JSON file with a new or existing XML webresource ignoring the fact that it is JSON instead of XML. Now we have to manually copy paste the content in the webresource editor.