The content of the ccSubSDK folder are piling up with files. This is the folder where submissions are staged for delivery to Symantec.
Default Folder Path: C:\ProgramData\Symantec\Symantec Endpoint Protection\CurrentVersion\Data\CmnClnt\ccSubSDK
The machine does not have access to the internet, or communication to the internet is broken.
This may also be caused by a rapid increase in submissions due to a threat outbreak or false positive detection.
Ensure the correct proxy settings are set under Proxy Server tab in External Communications section for the specific SEPM group.