# “Mathjax is not defined” JavaScript error and no toolbar is shown and preview doesn't work on Mathjax-enabled sites

This is reproduced on Math SE and Electronics SE. I assume it is reproduced on all Mathjax-enabled sites.

Currently if I try to open http://electronics.stackexchange.com/questions/ask and ask a question in Firefox or Chrome the preview won't work. Here's a screenshot:

You see, there's no text in the preview area, no toolbar and there's a "Mathjax not defined" error message in the JavaScript console. Firefox console shows the same error message.

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Humm, it works for me. Have you tried refreshing your cache? What do you see when you go to cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML? – Matt May 25 '12 at 9:59
@Matt: FF says it can't reach the server. – sharptooth May 25 '12 at 10:01
No repro in Chrome 19 stable. The only error I see is Uncaught TypeError: Object #<HTMLStyleElement> has no method 'createTextNode' – Cody Gray May 25 '12 at 10:09
Is this still happening for you? Have you checked for proxies / filters that might be blocking cdn.mathjax.org? – Shog9 May 26 '12 at 6:43
@Shog9: Yes, it is still there and the link to Mathjax CDN still wouldn't open and I can't find any explanation for that so far. Perhaps some temporary network-related problem. Still it should not have affected the toolbar and the preview. Do I create a separate question on that? – sharptooth May 28 '12 at 5:31
On mathjax-enabled sites, the editor and especially preview depend on having the mathjax scripts available - without them, they'll tend to break. You might want to talk to your network administrator or ISP about this. – Shog9 May 28 '12 at 5:34
@Shog9: You can't insist on all sites being available 24/7 on the Internet, it just won't work. Yes, the toolbar and the preview could break, but they should break only partially, not completely. How big is the percentage of people using MathJax? How big is the percentage of posts where MathJax is needed? I wanted to ask a question without anything needing MathJax (and btw I have no idea how to use it), and all I could see is there was no toolbar and no preview. As a developer I can hear your objections, but as a user I'm sure this can be improved. – sharptooth May 28 '12 at 5:46
We don't depend on all sites - just the handful that serve the code that drives these sites. Can you try running a traceroute on cdn.mathjax.org and post the results here? Also, see if you can load c328740.r40.cf1.rackcdn.com/mathjax/latest/MathJax.js – Shog9 May 28 '12 at 6:01
@Shog9: Nope, that one doesn't open either. The traceroute to Mathjax CDN doesn't get past the corporate network addresses. Don't get me wrong - I don't say there should be no dependency on Mathjax or anything else, I only say that dependency should not be so strong, that's it. – sharptooth May 28 '12 at 6:12
Yeah, that'd be a separate feature request then. I see your point - but you should still try to figure out what's preventing you from hitting the mathjax/rackspace CDN. – Shog9 May 28 '12 at 6:22
The error "ReferenceError: MathJax is not defined" appears here as well, and the cdn.mathjax.org is blocked in my company (don't know which filter). It worked till last Friday. – huebe May 28 '13 at 7:50