Opened the Console > Settings > All Settings > Software > Patch Management > Windows Settings > Windows Patch Remediation Settings; click the Apply To and found that the Available Targets selector lacked the Windows Computers with Software Update Plug-in Installed Target.
Opened the Console > Manage > Computers > Targets > System; found some addition Solution targets were missing. Found under this path; the default folder under was not present.
Confirmed the Altiris Patch Management Solution folder was to be housed there and was missing.
ITMS 7.5.x, 7.6.x and 8.x
Cause appeared to be environmental for there was no sign of corruption in the SMP Logs nor installation logs from the last upgrade.
Work through the following remediation steps:
Prerequisite is to have the correct ParentFolderGuid assigned.
Found this was lost in the environment and created a new folder for them which provided a new ParentFolderGuid