Agents are unable to send basic inventory or download packages successfully. The agent logs show that the response when attempting to communicate is 'Catastrophic Failure':
Failed to send basic inventory
Error: Catastrophic failure (0x8000FFFF)
ITMS 8.x
The error indicates that communication was successful, but the server was unable to process the request or information. One possible cause is the hard drive being full.
Adding more disk space, or freeing up existing disk space can resolve the issue if the drive is full. Otherwise look over the SMP logs, and Event Viewer logs for any other environmental conditions that would prevent the NS from proccessing correctly.