Symptoms

When ProxyPreserveHost is set to OFF in Apache HTTPd's configuration, several issues can ensue:

1. Rich Text editor does not display - CONF-13942 (fixed in 2.10.1)
2. Some configurations with Trusted Applications may not work (if the server base URL differs).

Cause

ProxyPreserveHost is set to OFF in Apache's configuration.

Workaround

To work around the issue, in Tomcat's server.xml, use:

<connector proxyName="hostname" proxyPort="80" />

This is described in Tomcat's documentation.

Resolution

Atlassian recommends using ProxyPreserveHost ON.