in research to check a possible fix of a bug (http://forums.b2evolution.net/wrong-link-building-in-post-moderation) I tried to run cleaning tools from maintenance.
Running "Find and delete all orphan File objects (with no matching file on disk) - DB only" I get a message that 34 invalid entries were found (see fig. 1) and that I should run "Find and delete all orphan file roots (with no matching Collection or User) and all of their content recursively - Disk & DB" But running this cleaning command no entries were deleted. (see fig. 2)