After upgrading to a new ITMS version, in client's Symantec Management Agent's GUI, software updates tab is displayed as 'Software Update Plug-in is not ready'.

Error1:

source='Agent' module='AeXNSAgent.exe' process='AeXNSAgent.exe' pid='6536' thread='4044' tickCount='22776582' >
  <![CDATA[Failed to create object 'Altiris.SoftwareUpdateAgent': The object is not registered or is not present in the policy (0x8000401B)]]>

Error2:

source='Software Update Agent UI' module='PatchMgmtAgentsUI.dll' process='AeXAgentUIHost.exe' pid='6276' thread='4076' tickCount='22776582' >
  <![CDATA[Failed to get SoftwareUpdateAgent from Symantec Management Agent. Please check that the Software Update Agent policy is enabled]]>

ITMS 8.1, 8.5, 8.6

1. It appears there is an issue with the ability of the user, even Application Identity, to have more than read only rights to the filter. This has been known to occur when an account other than the application identity account has been used to repair the SMP or Patch solution or otherwise modify the DB. It is strongly advised to ensure that all changes made to the DB or SMP (repairs or otherwise) are executed with the App ID credentials and logged in with the MSTSC /admin switch.

2. The "Default Software Update Plug-in Policy" (under Settings>Agents/Plug-ins>Software>Patch Management>Windows>) was not containing any target.

Clone the "Default Software Update Plug-in Policy" and add the filter "All Computers with Software Update Plug-in Installed Target"

OR

Verify that the affected client machine(s) belong to the assigned target for this "Default Software Update Plug-in Policy". Especially that the main target is not calling other filters that can be excluding them.

154143 "Management Agent GUI displays: 'Software Update Plug-in is not ready'"