This is compiled by Handlebars into JS source code that includes helpers.null and depth0.null. IE 8 gives a syntax error, "Expected identifier", when Handlebars tries to compile this to a function.

I've put up a Handlebars patch to fix it upstream, but in the meantime we can also use {{~noop~}}, which I believe has the exact same effect, and may be more intuitive anyway.

This causes major user-facing problems, e.g. it can't render new topics at all.