This is a problem with printfriendly.com itself. It is redirecting the page to its old version, which does not read the content.
But you can make it work. Follow the below steps ..
Open wp-socializer.php file present in the wp-content/plugins/wp-socializer/ folder
Goto line 407
Replace the line
‘url’ => ‘http://www.printfriendly.com/print?url={permalink}’,
with
‘url’ => ‘http://www.printfriendly.com/print/new?url={permalink}’,
save the file. That’s all.
Regards,
Aakash Chakravarthy