Unified Agent (UA) intermittently fails to connect to WSS. The message in the UA log says "Unhandled exception in CTC Check" and UA stays in failure mode.
Example of Unified Agent Diagnostics logs : -
[12-03-2018 07:53:01 (UTC+1:00)]: ---- Starting Service (18.104.22.168009)---
[12-03-2018 07:53:35 (UTC+1:00)]: Unhandled exception in CTC Check
[12-03-2018 07:53:35 (UTC+1:00)]: Customer ID: xxxx
[12-03-2018 07:53:39 (UTC+1:00)]: Windows 7 Enterprise x86_64 6.1.7601 Service Pack 1 machine name: SYMCTEST machineID: 89c03c6f-xxxx-452a-xxxx-cf8ad8cxxxx
Unified Agent is end-of-support and should be upgrade to WSS Agent (current available release is 7.5).