Found a PHP8 bug in this version.
If I use the function "check for new images" (German: Neue Bilder checken) and there are new images in the chosen category (which I've uploaded upfront via FTP) you will see nothing (because there is a not displayed error).
The problem is in the file admin\checkimages.php at line 836.
Here you have to change
if (!@in_array($image_list_all[$key][$i], $image_list_sql[$key]))
to
if (($result->num_rows == 0) or (!@in_array($image_list_all[$key][$i], $image_list_sql[$key])))
If you aren't experienced enough to change this, you can load my attached fixed file and replace it at your webspace.
Would be cool if the 4images guys could add this fix to there 1.9(.1) package.