API key login successful, session create successful. But can't get test set entity.

Get error:

Failed to execute the test, Exception: com.microfocus.application.automation.tools.common.SSEException: org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 3; The markup in the document preceding the root element must be well-formed.Empty Results

That's checking the test set existence.

The issue is that the cookie was lost.