When trying to go to Licensing in the Notification Server console, the following error appears:
Altiris Notification Server Error
The following error occured on the page 'cfgLicensing.aspx':
An existing connection was forcibly closed by the remote host
Service Pack 3 R6 for Notirication Server didn't install properly.
Repair the SP3 for Notification Server 6.0. Go to Add or Remove Programs > Altiris NS 6.0 SP3 Update (KB34317) > Modify > Repair.
Notification Server 6.0 SP3 R6
In this case, SP3 R6 had been installed, but it was only reporting "6.0.6027 (SP3)" in the top-right corner of the console. It should display as "6.0.6027 (SP3 + R6)".