When you try to start SUM Java page, “HTTP 404 Not Found” page comes with “Unable to open connection file …… Permission Error” log message in the host agent sapstartsrv.log file.

Web page should be look like below screenshoot ;

In this case, sapstartsrv.log file contains following messages ;

Solution ;

Please add “SAP_LocalAdmin” user group to the list of permitted parties for folders and files below the <Drive>:\usr\sap\ directory.

Then try to logon related web page again.