Su-post generates a lot of errors when in debug mode

We had a problem when testing in debug mode.
In the page is:

[su_posts template=”templates/default-loop.php” id=”” posts_per_page=”5″ post_type=”post” taxonomy=”category” tax_term=”11″ tax_operator=”IN” author=”” meta_key=”” offset=”0″ order=”DESC” orderby=”date” post_parent=”” post_status=”” ignore_sticky_posts=”no”]

The problem is caused by the thumbnails. The function seems correct in the template, but for unkown reasons it generantes a lot of error boxes (about 30) before displaing the picture at the borrom of the page. I tested with only 1 post to display.

I can not find out why this item is in a loop with wrong parameters. Deleting the part used to display the thumbnail, makes that there are no errors. The errors tell that the Object is wrong.

Please have a look at this by enabling ‘debug’in the config.