# Braces don't render in preview

When I type braces in math mode in a post, like $\{1,2,3\}$, they don't show up in the preview. See the following screen shot.

I tried all the different Math Renderer options, and disabling Fast Preview, with the same results.

This affects the main MO site, but not Meta.MO (so don't try to test it on this post).

When I submit the post, the braces show up correctly. Likewise, existing posts seem to render fine, but if I try to edit them, I don't see braces in the preview.

Typing $\\{1,2,3\\}$ makes the braces appear in the preview, but I expect this would mess up the output in the actual post.

I'm pretty sure this just started recently, as I think I would have noticed it before.

I can reproduce this with Firefox 42.0 on Ubuntu and Safari 9.0 on iOS (using the Full Site).

• Same here; also on Firefox on Android. – Asaf Karagila Nov 22 '15 at 18:22
• I never got braces to work. I use \lbrace and \rbrace – Benjamin Steinberg Nov 22 '15 at 22:19
• Same on chrome 46.0x on mac – Gabriel C. Drummond-Cole Nov 22 '15 at 23:39
• Another problem that seems very related ("not enough escaping"). A wild guess where this comes from: the citation helper Based on nothing but the problem ought to be recent and this being a recent changed. And the problem being only present on MO, at least not on math.se and matheducators.se, (neither having the citation helper). – user9072 Nov 23 '15 at 18:26
• I am seeing this behavior again, at least sporadically. Is anyone else? – Mike Shulman Aug 25 at 19:01