Looking at the log there are two things:
1 - Did you manually remove/modify the Core Server name in the log? If not, then it might not be set properly. You can find more information here: How to change Core server name in WinPE?
2 - You can get more details about why the download failed by enabling XTrace for lddwnld. This will add a lot more information to the log about what is happening, as well as details about any errors. This document can help with enabling XTrace: How to enable XTrace Diagnostic logging for the LANDESK Core and Clients