XnView Software

I have moved most of my images to an archive folder position on another internal drive. Now I notice the categories filter tab is confused. I need to know what a good workflow is to clean this up. Many of the old thumbnails that point to an image in the old folder are presented as blank images. In the Settings/Browser/Catalog tab a number of options are presented. I do not know that those might do (good or bad) if I select on of those. I have also tried to use View/Update Catalog from files but that didn't seem to do anything here.

Can someone point to a good place to learn about catalog maintenance?

Thanks in advance. XnView is still a great tool, just a steeper learning curve for me.

First, can you tell us if categories were saved as keywords ?
(to check this, select sample photos, look in IPTC tab or XMP tab ... )
And I suppose that you are only talking about jpg photos ...

If you can see corresponding keywords (iptc keywords, or xmp subject, or xmp hierarchical subject, or xmp sidecar files ?) , it means that you have (fortunately) used "Settings, metadata, export options" and you will be able to rebuild the catalog.

If not, you should copy your xnview.db file for backup, and ask Pierre for the easier method.

It will be perhaps possible to use carefully "settings, catalog, relocate" for each folder, or "Settings, Catalog, base path"for the whole catalog if folders have kept the same structure.
Another way is to manually tune the content of xnview.db file with a software like DB Browser for SQLite.