For a remote Web server installation the Web server plug-in configuration service propagates the plugin-cfg.xml file automatically for IBM HTTP Server only.
For all other Web servers, propagate the plug-in configuration file manually. Copy the plugin-cfg.xml file from the profile_root/ config/ cells/ cell_name/ nodes/ web_server_name_node/ servers/ web_server_name directory on Application Server. Paste the file into the plugins_root/ config/ web_server_name directory on WebServer Plugin.
In your case please check any configuration is updated on the magnus.conf and obj.conf files with the Plugin file location and check the plugin logs to see it has loaded properly with the WebServer.
Also Please provide the version of WebSphere Application Server/Sun one webserver and operating system