"Show Page Number" option not working in Adobe Digital Edition 4.5.7

Hi,

I am previewing my ePub file on ADE latest version 4.5.7. This reader has an option "Show / Hide Page numbers" however while clicking on "Show page numbers" option, it is not showing/display any page numbers in ePub.

I am wondering if it is a bug in ADE or do we need to include any additional code or file (page-map) in the ePub package.

Please advise.

Regards,

Naushad