Salesforce CRM Command Line Interface (CLI) Data Loader reports com.sforce.ws.ConnectionException:
Failed to parse detail: START_TAG seen ...</sf:exceptionMessage><sf:upgradeURL>
An outdated version of Data Loader and / or Java tries to connect to Salesforce using TLS 1.0.
Upgrade Salesforce Data Loader to the Latest Version:
This can be downloaded from a Salesforce org by navigating to: Setup --> Data Management --> Data Loader.
Upgrade the Java JRE that Salesforce Data Loader uses to JRE 8 or above.
Salesforce Community: Salesforce Community Forums