The metadata is a description of the content, rather than the actual content itself - it says which categories and products the files are part of, what type of file they are, what they are compatible with. What is happening with the Smart Content pane, and are other containers that depend on the database OK - the presets tabsd in various property panes, Categories and products in the Content Library pane, and the type tags (Actor, materials etc. at top-right of a file's thumbnail) in the Daz Studio Formats tree?

Daz Central is a simplified interface for Install Manager, Daz Connect is the system for installing through Daz Studio itself (Install pane or Smart Content pane or Products in the Content Library pane)