ketoweb

Disable WP-Rocket Cache and only use APO for Caching.

Deleted all the caches. Problem Fixed thanks to t-p.

Cheers Guys!

Working for me now, but @mike price it seems like my website is not working from russia, Canoga Park CA, United States, London United Kingdom according to the link that you have given.

What should I do to fix that?

You can use duplicator to move your WP MU site. I did it recently. Anyways, Its really easy to move sites from one host to the other. I would recommend you to go for some Linux host that has cPanel.

Also, the fetch as Google is giving error as the website is temporarily not accessible. what should I do to fix this?

Just figured it out. I had to go to the advanced dns zone editor on my cPanel and delete the webdisk.mydomain.com entry. This entry was conflicting with the subdomains. Not it is working fine.

Hosting that I am using is : HostGator.

If it is a premium theme, then you should contact the developer of the theme. Check line 19 of that file anyways, there must be some issue with it.