Group visibility error: ArgumentError: comparison of String with 0 failed

https://sentry.gitlap.com/gitlab/gitlabcom/issues/217867/

ArgumentError: comparison of String with 0 failed
  project.rb:1489:in `<='
    level <= group.visibility_level
  project.rb:1489:in `visibility_level_allowed_by_group?'
    level <= group.visibility_level
  gitlab/metrics/instrumentation.rb:159:in `block in visibility_level_allowed_by_group?'
    .measure { super }
  gitlab/metrics/method_call.rb:36:in `measure'
    retval = yield
  gitlab/metrics/instrumentation.rb:159:in `visibility_level_allowed_by_group?'
    .measure { super }
...
(128 additional frame(s) were not displayed)

comparison of String with 0 failed