query select content_type as object_type from cr_items where item_id=-4 did not return an answer
    while executing
"error "query $sql did not return an answer""
    (procedure "::xo::db_1row" line 8)
    invoked from within
"::xo::db_1row get_class_from_item_id  "select content_type as object_type from cr_items where item_id=$item_id""
    invoked from within
"ns_cache eval xotcl_object_type_cache  [expr {$item_id ? $item_id : $revision_id}] {
      if {$item_id} {
        ::xo::db_1row get_class_from_item_i..."
    (procedure "get_object_type" line 3)
    ::xo::db::CrClass->get_object_type
    invoked from within
"my get_object_type -item_id $item_id -revision_id $revision_id"
    (procedure "get_instance_from_db" line 2)
    ::xo::db::CrClass->get_instance_from_db
    invoked from within
"::xo::db::CrClass get_instance_from_db -item_id [$page parent_id]"
    (procedure "get_folder" line 22)
    ::202174 ::xowiki::Page->get_folder
    invoked from within
"$page get_folder -folder_form_ids $folder_form_id"
    (procedure "build_tree" line 19)
    ::nsf::__#Q ::xowiki::includelet::folders->build_tree
    invoked from within
"my build_tree"
    (procedure "render" line 14)
    invoked from within
"next"
    (procedure "render" line 4)
    ::nsf::__#Q ::xowiki::includelet::decoration=plain->render
    invoked from within
"$includelet render"