# Undefined control sequence \\textcolor
**URL:** https://meta.discourse.org/t/undefined-control-sequence-textcolor/372840
**Category:** Bug
**Tags:** math
**Created:** [July 3, 2025, 9:08pm UTC](https://meta.discourse.org/t/undefined-control-sequence-textcolor/372840 "2025-07-03T21:08:27Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 3, 2025, 9:08pm UTC](https://meta.discourse.org/t/undefined-control-sequence-textcolor/372840/1 "2025-07-03T21:08:27Z")
Hi,
my instance has been using MathJax for a while.
Oftentimes when there are many `$…$ `or $$…$$ trying to render at once they all abort with `undefined control sequence \textcolor`
This has been happening for years, and my solution was to make the majority of my userbase moderators so they could press the pencil, save the edit, and then get a perfect render.
Due to the unpredicatability of the issue, i’d probably struggle to provide my own logs. However, this bug has become visible today here on the Meta (with no edit or leaving of page)
[ ](https://www.youtube.com/watch?v=67Evm1DL5AE)
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### Author:  [@j.jaffeux](https://meta.discourse.org/u/j.jaffeux)
#### Post date: [July 5, 2025, 10:14am UTC](https://meta.discourse.org/t/undefined-control-sequence-textcolor/372840/2 "2025-07-05T10:14:02Z")
I don’t know, but I suspect that would go away if we did update mathjax library, problem is that they did very significant changes so it’s not an easy project.
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### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [May 31, 2026, 7:58am UTC](https://meta.discourse.org/t/undefined-control-sequence-textcolor/372840/3 "2026-05-31T07:58:54Z")
You’re right. It does seem to have gone away after
> [@Upgrading Mathjax to version 4](https://meta.discourse.org/t/upgrading-mathjax-to-version-4/392669):
>
> @sam and all interested in typing math in Discourse. I’ve updated the discourse-math plugin so that it uses MathJax V3, rather than the much slower and very outdated V2. As expected, the result is a much snappier user experience, while still maintaining the feature rich environment as compared to KaTeX. I’d love to issue a pull request, if you think the results look good. You can see it in action on my class Discourse site: Most of the content on that site is private or unlisted. There sho…
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### Author:  [@sam](https://meta.discourse.org/u/sam)
#### Post date: [June 1, 2026, 2:59am UTC](https://meta.discourse.org/t/undefined-control-sequence-textcolor/372840/4 "2026-06-01T02:59:40Z")