SUM fails to start correctly on AIX, also unable to connect using the GUI

SUM fails to start correctly on AIX, also unable to connect using the GUI.

You will also see  somestimes a HTTP 404 error.


When you start the SUM service you are unable to connect using the remote GUI.
Checking in the host control directory you find errors, including possibly:
[Thr 515] *** ERROR => Received a corrupt CommunicationHeader [Communicatio 175]
[Thr 515] *** ERROR => Header could not be read [Communicatio 154]
[Thr 515] *** ERROR => ProcessWatcher::Loop: More that 100 messages corrupt. Exit from ProcessWatcher::Loop [ProcessWatch 252]


Issue is resolved as follow.

Run CALL R3SAP400/SAPINIT

If there is still issues with connecting to SUM, update the SAPHOSTAGENT on your system

or else check the authorisations on the directories under /usr/sap/hostctrl/.