Table in XWiki15.3 not visible

We are about to introduce XWiki in our university library as knwowledge base, and the feature of having a review mechanism to check pages for actuality every x months is one of the most wanted. So far the extension works quite well, you can add pages to the review list. Unfortunately you can't see the actual entries in the list:

although you can see, that there should be 4 items to be shown. I already searched in the sources, but without any clue.

Is there any way to fix this?