You speak of "gallery
items", which is a setting for the page
gallery ... yet your screenshot is from the menu, which has nothing to do with the page gallery layout. Setting item "preview" in page gallery settings, just means the gallery layout on the page will show previews of the images. The MENU requires a preview image assigned to the page.
- Did you assign a preview-image for these new pages?
- Preview images are assigned automatically if the pages contain images.
- If none of the above are set, then X3 will use your default preview-image (settings -> page -> details).
- If you haven't assigned a preview-image for the page, and the page itself does not contain images, and you have an invalid "default" preview-image, then how is X3 supposed to locate a preview-image for each page to show in the menu?