Linter URL displays characters that cannot be read in Greek

Does someone know why this happens? This is a WordPress site. 3 other Web sites to be developed in the Greek work perfectly.

Here's the result Linter:

Http://developers.facebook.com/tools/lint?url=http%3A%2F%2Fwww.goldenmag.gr%2Farchives%2F24754

Here's the header of the site ("el" is Greek):

And here's the meta code:

Thanks in advance

Last edited by mixalakis123 (now 04: 28: 25)