When trying to send packages to clients through policies or tasks immediately rather than on a future schedule the clients may stay in a retrying download status for up to an hour and report "No package sources returned by server." This is normal behavior because the Package Server that will stage the package must update its configuration to receive a new package policy and by default Package Servers update configuration on a one-hour schedule. The package may then take a couple minutes to download to the package server and have its source location reported back to the NS\SMP server. Clients don't receive the new source location until their next download attempt.
If a package is required immediately, follow these steps to manually force a package download to the Package Server and client:
1. On the Package Server open the Symantec Management Agent and then the Settings menu. Click the Update button and watch that the "Requested:" and "Changed:" dates update. Go to the Package Server tab and wait several minutes while the packages refresh to confirm that the desired package appears, downloads, and becomes ready.
2. The package should download to the client on its next download attempt (wait a few minutes). To download a package immediately for a Managed Software Delivery policy open the Agent on the targeted client machine, go to the Software Delivery tab, select the desired policy from the list, then click the Download button under the Package Tasks pane in the upper left. To monitor the progress of the package download double-click on the desired policy and go to the Download History tab.