We have WebLogic 10.3 and Apache 2.2 running on Solaris. When a request sent by web browser, it returns 200 and works normally...
But when the same URL is sent by mainframe, it returns 400 and WebLogic logs says;
Have you configured clustering? If so, check to see if "WebLogic Plug-In Enabled" is set to true in Advanced section of cluster configuration.
If not set to true. If clustered it overrides server setting.