Attachment Selector - doesn't work

Hello,
I wanted to create a list of attachments on a specific page, so the user is shown this list without the need to click on “attachments” tab at the bottom of the page (which is also limited to 5 entries by default). I thought the Attachment Selector macro could help me, but I can’t make it working.

My page is located at xwiki:A1.B1.Files.WebHome and it has 2 attachments (a pdf file and a jpg file).
I put xwiki:A1.B1.Files in the Classname field and attachedDocument in the Property field of the Attachment Selector (inserted from the Insert → Other Macros → Select Macro menu). But nothing happens. The macro is completely empty. I also tried it in xwikiplayground Sandbox with the same result.

Any help is highly appreciated.