It's true... confirmed. Funny that worked on localhost. Anyway, to fix, open admin/applications/forums/extensions/usercpForms.php and find: $blocked[] = $this->registry->getClass( 'class_forums' )->forumsBreadcrumbNav( $fid['id'] );
Change to:
$blocked[] = $this->registry->getClass( 'class_forums' )->forumsBreadcrumbNav( $fid );
Now it's ok. Tested online on my board.
I will update new zip file but will keep the version.
Tks.