Error displaying categories

[Bert Heijenga]

Finally I  succeeded in the migration process. I made the menuitem "categories" and when I click on it I see all the categories I made. But when I click ON a category the only thing I see is this (screenshot 1) When I click on 'geavanceerd zoeken' (advanced search) I only see ONE book (screenshot 2). What did I do wrong?

[federica]

Hi Bert,
if you have not already done, try to update joomla to the latest version