This occurs on the latest 9 Cordova version (as well as a previous one that I updated from, I believe 8.x).
Referencing : #39
Just installing the plugin and running the app springs up this error.
2019-04-12 11:59:30.979 21202-21310/com. W/CordovaPlugin: Attempted to send a second callback for ID: networkinterface1757067064
Result was: "Invalid action"
2019-04-12 11:59:30.981 21202-21310/com. W/CordovaPlugin: Attempted to send a second callback for ID: networkinterface1757067065
Result was: "Invalid action"
This appears to explain the error (or be a symptom of) when I call getHttpProxyInformation:
Unable to get proxy info: Error while calling ''getHttpProxyInformation' 'protocol = null host = null
2019-04-12 11:59:30.992 21202-21202/com.GPSWalking.Team10 I/chromium: [INFO:CONSOLE(157)] "Unable to get proxy info: Error while calling ''getHttpProxyInformation' 'protocol = null host = null", source: http://192.168.1.128:8100/__ion-dev-server/ion-dev.js?v=3.2.2 (157)