Exact cause is unknown. It could be:
1) Ensure that the Task Server component is working correctly on the Notification Server (This appeared to be a crucial step in the troubleshooting process)
...You can verify this by:
i- Navigating to Settings -> Notification Server -> Site Server Settings
ii- Navigate to Site Management -> Site Servers -> NSServerName
iii- Ensure that the Task Service shows up as "OK" with a service status of Active
2) Stop the Altiris Services (Altiris Service, Altiris Support Service)
3) Using SQL Management Studio perform the following steps against the Symantec_CMDB;
NOTE; It is recommended that you back up your database and/or the contents of the TaskManager table before you perform any direct modification of the database. Modifying the database in this manner could cause corruption requiring you to restore the database to its state before performing any of these modifications.
Select the proper database and run the following query;
SELECT * FROM TaskManager
This will show you the contents of the table containing the task statuses. A common occurence when seeing this problem, is that one or more tasks will have a EndDateTime value of NULL. If you see one or a few of these occurences you may choose to remove just these, which should address the problem. Alternatively you can truncate the whole table, if removing the few offending entries does not fix the problem or if you cannot easily identify the offending entries.
To remove the entries with the NULL EndDateTime value run the following query;
DELETE from TaskManager
WHERE TaskManager.[Name] like '%TASKTYPE%'
and TaskManager.[EndDateTime] is NULL
The TASKTYPE value in the query should be substituted with the proper task type as seen in the [Name] column of the offending entry/entries. If there are multiple types you can run the query each time for each type or you can run the following query that does not perform a check on the task type;
DELETE from TaskManager
WHERE TaskManager.[EndDateTime] is NULL
To remove all contents of the table run the following query;
TRUNCATE TABLE TaskManager
4) Start the Altiris Services (Altiris Service, Altiris Client Message Dispatcher, Altiris File receiver, Altiris Support Service)
5) Close any open NS console windows
6) Navigate back to the AD Import screen and try running your Import again.
It should work at this point.
Notification Server 7.0 SP3
Active Directory Importer 7.0