Updating ITMS from 8.5 RU3 to 8.5 RU4 fails during configuration of Monitor Solution with error code 1603.
NOTE: Please verify that you are logged in to the Notification Server (NS) as the Altiris Service Account/APPID.
First, verify that there are no partial installs by typing CTRL-Shift-P at the main Symantec Installation Manager (SIM). When you type CTRL-Shift-P at the main SIM page, "Partial installs" (in yellow below) shows. If the section in blue shows blank, type CTRL-Shift-P again to take you back to the main page.
In the SIM, choose "Repair Installed Products", then choose "Reconfigure Installed Products", click "NEXT" and then choose the proper Solution and the correct version/RU.
Caution: Please verify that you have chosen to reconfigure the correct version and RU, in this case 8.5 RU4.
In this case, we choose "Altiris IT Management Suite 8.5 RU4."