A.logs (NS Log files) contain pairs of errors regarding InventoryRuleManagement as shown below.

System.Net.WebException (System): The remote server returned an error: (401) Unauthorized. 
 

Unhandled exception. 
System.Web.HttpException (System.ServiceModel): The service '/Altiris/InventoryRuleManagement/Agent/InventoryRuleService.svc' does not exist. 

Solutions are partially installed and need to be configured.

Open Symantec Installation Manager then click Ctrl+Shift+P to show any partially installed solutions. Click Ctrl+Shift+P again to hide partial installs and click on one of the solutions that was partially installed. Click Reconfigure and Symantec Installation Manager will begin reconfiguring all partially installed solutions.

Note: If SIM doesn't show any partially installed Solutions, run a repair in the actual "altiris_inventoryrulemanagement_7_5_xxxx.msi" file:

a) from the command prompt running as administrator, run:

msiexec.exe /i "C:\programfiles\altiris\symantec installation manager\installs\altiris\altiris_inventoryrulemanagement_7_5_xxxx.msi" skipaim=1

b) you may be prompted to select between install, repair, remove. Select Repair.