I have opened or imported a PAGX layout in VSP Designer, but the layout looks different to the one in ArcGIS Pro. What might be the problem and how can I solve it?

If you use the VSP Designer in ArcGIS Pro Layout Mode you can create, update, open, and import ArcGIS Pro layout files in your browser. In this case you don't need an ArcGIS Pro installation on your host to edit printing layout templates. Though regardless of if you create a layout template from scratch in VSP Designer or you are importing an existing PAGX layout template from ArcGIS Pro, the result will always be a PAGX layout template as soon as you save or export the layout in VSP Designer.

This means that the layout configurations are converted between a web-based view (VSP Designer) and a desktop-based layout format (what you see when editing the layout in ArcGIS Pro). Since not all ArcGIS Pro layout properties are supported in VSP Designer, the layout configuration in the browser might look slightly different to the layout configuration in ArcGIS Pro. In general, VSP Designer is designed for supporting the most commonly used and the most important properties from PAGX layouts, to have the best balance between functionality and usability when editing layouts in Web. If you are missing important layout properties, please contact VertiGIS Support.