It’s really good news for me. I got again default features of WordPress 🙂

These features are

• Preview of theme
• Preview changes of post

I tried to change some codes from function.php and reinstall WordPress again but these options didn’t solve my problem.

So let’s explain what you have to do.

1. Go to Settings -> General settings
2. Check your Url address it should be without www

Not Corrrect http://www.domain.com or http://www.subdomain.domain.com

Correct         http://domain.com or http://subdomain.domain.com

I think that problem appear because of Polylang that I use for bilingual website.

Hope that helps someone else!