Unable to add remote node in Rundeck 4.9.0
Following the doc from Rundeck, however the only button I have under "Sources tab" is "ResourceModelSource"
When I click that button I get a blank 
PPS Issue happened on previous version - new to RunDeck, so I can't say that it EVER worked
I tried adding a manual resouces.xml in the project director y(Which I had to manually create, which tells me that's another issue) and reloading RD but that did not seem to work
While it's not the likely cause, I'll mention it here incase it IS relevant, I'm hosting on port 4440 however I'm using nginx to forward http (not https) requests on 443 to 4440, this is due to corp net sec policy.
I'm sure it's something where it's having an i/o issue on the local host, however I'm not seeing anything in the logs.
That is a known issue when you have Rundeck installed behind a proxy server, take a look at this: https://github.com/rundeck/rundeck/issues/6278 the solution is to set the grails.ServerURL (rundeck-config.properties file) with the exit URL defined for Rundeck in your proxy server (e.g: grails.serverURL=http://my_domain/rundeck), then restart the Rundeck service.