After enrolling the on-premise Symantec Endpoint Protection Manager (SEPM) 14.2 RU1 into the cloud, you notice from SEPM > Cloud > Troubleshooting page shows "Error" on Assets, Events, and Connector for the Connection Status.
uploader.log:
<time_stamp> [8608:8076] [SEVERE ] We cannot get EPMP access token. Notify to detect/update proxy state...
sepcloudhub.<date>.0.log:
<time_stamp> [Interrupt signal hook] ERROR c.s.p.hub.common.HubRunningStatusDAOImpl - backupMarkerFileToDbAtShutdown> Unable to backup marker file for Agent: ASSET_COLLECTOR idx: 23B32C70D6604EE89A7AFD3A8A95E590
<time_stamp> [Interrupt signal hook] ERROR c.s.p.hub.common.HubRunningStatusDAOImpl - backupMarkerFileToDbAtShutdown> Unable to backup marker file for Agent: EVENT_COLLECTOR idx: 8D74BE3FE173430293341FBCFD5FA40A
More than one SEPM in the site.
Proxy was not allowing traffic to https://usea1.r3.securitycloud.symantec.com:443
This issue was resolved by circumventing customer's network proxy that blocked traffic between the SEPM and the cloud.