Forum doesn't appear for most users all of a sudden why?

[محروم.كوم]

Hi
My forum www.hsvforum.com.au since last Sunday decides not to show on lots of members computers and mobile devices. I have Apple devices and computers

and only the headers appear. But yesterday strangely it appeared again on the Apple Mac. Then today doesn't appear. Same is happening for my members not just me. My Host company is trying to find the issue but is struggling to find the problem. Some members are able to see the site and post and others just cannot load the forum part just the header. What could be the sudden issue? Everything has been working fine up until Sunday?? Please help
We have checked for hacking and it all seems clear. __DEFINE_LIKE_SHARE__