Messages Window
The Messages Window is displayed in XSLT and XQuery debugging sessions.
XSLT 1.0, XSLT 2.0, and XSLT 3.0
In XSLT debugging sessions, the Messages tab displays error messages, the xsl:message instruction(s), or any error messages that may occur during debugging.
XQuery
In XQuery debugging sessions, the Messages Window displays error messages.