Web pages showing gobbildygook

This issue has been occurring on and off for over a week now. Sometimes it appears on only one page, other times the entire website. All plug ins have been updated, and a corrupt file was found and deleted yet the problem persists.

Anyone have an idea what might be causing this? Any advice greatly appreciated.

http://www.ableproperty.ie/

When I say gobbildygook, I mean this:

[ Binary gobblygook redacted ]