EncodingError: Invalid Unicode [89 2d 56] at 0

https://sentry.gitlab.net/gitlab/gitlabcom/issues/4024701/?referrer=gitlab_plugin

EncodingError: Invalid Unicode [89 2d 56] at 0
  lib/gitlab/json.rb:130:in `dump'
    Oj.dump(object, opts)
  lib/gitlab/json.rb:130:in `adapter_dump'
    Oj.dump(object, opts)
  lib/gitlab/json.rb:52:in `dump'
    adapter_dump(object)
  lib/gitlab/json.rb:278:in `stringify'
    Gitlab::Json.dump(jsonified)
  app/controllers/application_controller.rb:141:in `render'
    super.tap do
...
(179 additional frame(s) were not displayed)