20 April 2018

> **Important**: [Review the documentation](https://docs.projectcalico.org/v3.0/getting-started/kubernetes/upgrade/) carefully before attempting an upgrade.
> You must upgrade to {{site.prodname}} v2.6.5 or later before you can upgrade to {{site.prodname}} v3.0.6.
{: .alert .alert-danger}

#### Bug Fixes

- Fix bug in parsing of empty namespace selectors [libcalico-go #856](https://github.com/projectcalico/libcalico-go/pull/856) (@caseydavenport)

#### Limitations

- **Offers only Kubernetes, OpenShift, and host endpoint integrations**: the
  OpenStack, Mesos, DC/OS, rkt, and Docker orchestrators have not been tested
  and are not supported. ({{site.prodname}} still supports Docker and rkt containers.)
  We plan to resume support for the OpenStack, Mesos, DC/OS, and Docker
  orchestrators in a future release.

- **GoBGP not supported**: Setting the `CALICO_NETWORKING_BACKEND` environment
  variable to `gobgp` is not supported. See [Configuring {{site.nodecontainer}}](https://docs.projectcalico.org/v3.0/reference/node/configuration)
  for more information. We plan to resume support for GoBGP in a future release.

- **Route reflectors cannot be clustered**: We plan to resume support for
  this in a future release.
