According to the wiki: "onResourceReady" "[...] is invoked when when all files are finished downloading to the client, and the resource is ready to start."

So any images that are supposed to be loaded, should be available by OnResourceReady Event, but actually this is not the case. I am actually trying to get Jacks speedometer running on my server since image loading doesn't work well for me somehow. And that is already some kind of a challenge... ^^'

So I added a simple console message to see when OnResourceStart is getting executed and well... It's running the code without being done downloading the whole resource at all.
But to be fair, this is only an issue when a player newly joins the server.
They have to relog to see the GUI Images...(Since they have been downloaded, but never loaded to the game session).