Error occured while publishing the Site Publishing Configuration [DM_METHOD_E_HTTP_POST_APP_SERVER_NAME_INVALID] error: "The app_server_name 'WebCache' was not specified in dm_server_config."
In Documentum Administrator. System -> Configurations -> Servers -> Info -> Tab AppServers
Look for this line:
WebCache http://localhost:6677/webcache/publish
If this line doesn't exists, run:
%DM_HOME%\product\5.3\webcache\install\config.exe