This occurs when the task is trying to use the wrong account type to logon to the database in the data query step. To resolve this, set the impersonation on the task to a user account that has permissions to connect to the database.
To do this:
Log in to TaskCentre.
Find and open the task.
On the General tab, click Options.
On the Impersonation tab, enter the credentials for the account to be used.
Click OK.
Click OK.