Can't register runner with example command

Using this example here http://docs.gitlab.com/ce/ci/docker/using_docker_build.html

sudo gitlab-runner register -n \
  --url https://gitlab.com/ci \
  --token RUNNER_TOKEN \
  --executor shell
  --description "My Runner"

I get the error:

Running in system-mode.

Token specified trying to verify runner...
WARNING: If you want to register use the '-r' instead of '-t'.
ion "My Runner"ERROR: Verifying runner... is removed               runner=******MY_TOKEN
PANIC: Failed to verify this runner. Perhaps you are having network problems

I dont have any problem using the sudo gitlab-runner register command and give the runner's info one at step