How to resolve illegal character code U+0003 in nomad job

Question

I am trying to run a nomad job that does a simple task of downloading a binary file from a remote repository. On running the job the nomad agent throws the error

Failed Artifact Download  failed to download artifact
"https://domain/releases/path/to/lib/version/lib-1.5.3.jar": error downloading
'https://domain/releases/path/to/lib/version/lib-1.5.3.jar': XML syntax error on line 1: 
 illegal character code U+0003

Below is my job specification:

job "job" {
  datacenters = ["dc1"]
  type="batch"
  group "download" {
    task "binary" {
      driver = "exec"
      artifact {
        source = "https://domain/releases/path/to/lib/version/lib-1.5.3.jar"
        destination = "/path/to/dir" 
        mode = "dir"
      }
      resources {
        cpu = 50 
        memory = 10
      }
    }
  }
}

I have done some digging and apparently this error means I have a # somewhere which I have checked and there's none. What could be the issue ?