Error "Downloading Software Update Package" returned when it appears to be running and going through the motions of "downloading" and then it fails at the very end of the download process as seen here:
The agent.log files on a sample managed machine show messages similar to:
Download package '{80862EA5-B80E-422F-A9C1-2B5BD00E8473}' from' \\<NS name>\NSCap\Bin\Win64\x64\Software Management\Plugin', local blocks: 0/1, server blocks: 0/0, bytes in cache: 0
Failed to download package '{80862EA5-B80E-422F-A9C1-2B5BD00E8473}' from: \\<NS name>\NSCap\Bin\Win64\x64\Software Management\Plugin, local blocks: 0/1, error: Bad Hash (0x80090002)
Download attempt completed: downloaded 0 bytes at 0 bytes per second, used 0 bytes from cache
Error while downloading package: Bad Hash (0x80090002)
Error while downloading package: No server found
ITMS 8.x
Firewall rules were blocking access to some shares on the Notification Server
Compared the Firewall rules to the Shares on the Notification Server (and Package Servers) to ensure Sym Agent machines were allowed access to the needed package download Shares.
Used the Microsoft Computer Management tool (compmgmt.msc) on the Notification Server (and Package Servers) to ensure managed machines had access to the needed package download locations: