Liquid XML is the ultimate XML Development and Data Transformation Environment including Graphical XSD Editor, XML Editor, WSDL Editor, XML Diff tool, JSON tools and the worlds most advanced XML Data Binding tool to generate C++, C#, Java, VB .Net and Visual Basic 6 code from your XML Schema (XSD, XDR, DTD).
Please update Visual Studio to the latest point release to fix this issue.
Blank Tool Windows in Microsoft Visual Studio 2019
Visual Studio 2019 now supports per-monitor DPI awareness (PMA) across the IDE. Unfortunately, a side effect of this is that some tool windows included in extensions from multiple vendors no longer work as expected and can render incorrectly or appear blank.
If you are experiencing this issue with blank Liquid Studio 2019 extension tool windows (e.g. Global Item Locator or XPath Expression Builder), uncheck the option 'Optimize rendering for screens with different pixel densities' in menu Tools->Options, setting page Environment->General.