You are using the Windows desktop application UPS WorldShip and it fails to communicate with its server while protected by the Web Security Services (WSS) with Unified Agent.
UPS WorldShip establishes an SSL connection to its server but it does not use the standard Windows certificate store, therefore it does not recognize the Cloud's certificate used for SSL interception.
To solve this issue, add the URL "www.wstd.ups.com" to either of the following configurations on the Web Security Service Portal: