problem with portfolio pages

Hi,

I am running WordPress 4.9.8, and Virtue 3.2.9 theme.

I have a problem that for all my portfolio pages I get an error:

“Sorry, but the page you were trying to view does not exist.
It looks like this was the result of either:

a mistyped address
an out-of-date link”

When I unpublish and hit view it is displaying correccty. One I publish i get an error. It was working before but it has stopped after I was having some other issues and was playing with those.

One thing I did was edit the header.php with the code to display facebook events.

<div id=”fb-root”></div>
<script>(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;
js = d.createElement(s); js.id = id;
js.src = ‘https://connect.facebook.net/hr_HR/sdk.js#xfbml=1&version=v3.1&appId=251600968747161&autoLogAppEvents=1&#8217;;
fjs.parentNode.insertBefore(js, fjs);
}(document, ‘script’, ‘facebook-jssdk’));</script>

I somehow doubt that is the reason because even when I removed it, it is still not working.

Regards,
Marko