@LesterChan: That didn’t work for me! Instead I restored my website using a backup I had made dated August 23rd 2014, before I had updated the plugin to version 2.54
Version 2.53 works perfectly fine on my website using the latest version of WordPress 4.0
I had looked more closely at the issues I encountered and I did noticed;
whenever the ‘print this page’ link is clicked, my webpage URL got suffixed with ‘\print’ instead of ‘\printpage’
In version 2.54, the suffix ‘\print’ is redirecting my webpage to my custom 404 webpage instead of displaying the print-friendly version of my webpage.
In version 2.53, the suffix ‘\printpage’ is successfully displaying the print-friendly version of my webpage.
Since I am using version 2.53 again on my updated website version 4.0;
Kindly advise me further on what I should do again please; before I update the plugin to version 2.54 again!!