file.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
Where exactly do you see this error message? Is it in a javascript error that you catch, or will it be printed to your console by the Meteor runtime? How exactly are you trying to access those files?
Then it indeed seems like a bug. My app is running on Meteor 1.9.2. With that revision I can access all files in the public folder even with a ROOT_URL with a folder parameter. I’ve also tried exactly your uri, /weltiq/1, and it worked. I don’t know why it fails in your app.