front static page stopped working

We have a live wordpress site that is now not displaying the front STATIC navigation page, it just displays the background.
Don’t know why this is happening but it seems whatever we try does not restore the front page. Have tried setting the blog as default but whatever browser is used to navigate to the site just displays the same blank page. Have even restored (IMPORT) from a backup taken back at the start of December.
Check it here
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Any help and guidance with this error would be much appreciated.
P.s. It does word OK on my andriod mobile, but not in windows or mac browsers!