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Have you edited any of your theme files?

I did not but someone else might have. How do I access the theme files?

Let’s not go there if you don’t know how to do it. First, check with that “someone else”.

It was a third party and i cannot get in touch with them.

If you don’t understand PHP, messing with the files could be a problem.

Let’s start this way: Disable ALL plugins and change the theme to twentysixteen. Is the problem gone? If so, re-enable things one at a time until the problem returns. Then we know on what to focus.