Community Help

OscarLevin

A recent update (some time between 4/9/2025 and 4/11/2025 seems to have broken a really important feature. To meet accessibility requirements, I have been creating HTML files that contain a lot of mathematics (using PreTeXt, which is sort of like LaTeX but can produce HTML correctly). Previously, I was able to upload the html file to "Files" and then let students view it from a Module. This correctly showed the math content displayed using MathJax, and other features of the webpage that used javascript worked correctly.

Now however, this seems to have stopped working. It was always the case that if you opened the file directly from the "Files" page, it didn't display the mathjax, but now there doesn't seem to be any way to make the page display correctly.

Any ideas whether this is a bug and if it could be fixed? Or is there something I could add to the HTML page that would let the mathjax through?

Note that reauthoring all my materials directly inside Canvas is a non-starter and upload PDFs is not allowed due to laws around accessibility my university is enforcing. Please help!

Thanks,

Oscar.

Gabriel33

It might be related to this post from the 10th. Not exactly the same issue, but also related to posting pages as files. Unfortunately without a solution yet:
Re: Issue displaying HTML file in Modules – Blank ... - Instructure Community - 639683

A reply to that post also mentions that this feature isn't exactly supported by Instructure, so it's possible that there won't be a "fix" for it.

Note that you can still paste html directly to pages, and math can be added by using expressions surrounded by , like $ x^2 $, or by $$ for expressions in its own line. I use those for quizzes.

dbrace

@Gabriel33,

For @OscarLevin and anyone else, would you be willing to share:

actual HTML code as an example
a screenshot of the HTML code
a screenshot of the RCE view after the HTML code has been added
a screenshot of Canvas displaying the item after it has been saved

-Doug

OscarLevin

To clarify, I am not pasting in HTML into the RCE (that definitely doesn't work, since Canvas sanitizes it beyond recognition). Instead, I am uploading the html as a file through the file browser. Until last week, adding the file as an item to a module, or linking to the file location as an "external link" would display the correct HTML and render the javascript mathjax correctly. Now the javascript does not work; in particular, the math is not rendered.

Attached are two screenshots of how this is (incorrectly) rendered. Apparently I can't upload an html file here, so I'll paste the html code below:

<!DOCTYPE html>
<!--********************************************-->
<!--*       Generated from PreTeXt source      *-->
<!--*                                          *-->
<!--*         https://pretextbook.org          *-->
<!--*                                          *-->
<!--********************************************-->
<html lang="en-US" dir="ltr">
<head xmlns:og="http://ogp.me/ns#" xmlns:book="https://ogp.me/ns/book#">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title></title>
<link xmlns:xlink="http://www.w3.org/1999/xlink" rel="preconnect" href="https://fonts.googleapis.com">
<link xmlns:xlink="http://www.w3.org/1999/xlink" rel="preconnect" href="https://fonts.gstatic.com" crossorigin="">
<link xmlns:xlink="http://www.w3.org/1999/xlink" rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@24,400,0,0">
<link href="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/css/theme-greeley.min.css" rel="stylesheet" type="text/css">
<link xmlns:xlink="http://www.w3.org/1999/xlink" href="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/css/ol-markers.css" rel="stylesheet" type="text/css">
<script>
var runestoneMathReady = new Promise((resolve) => window.rsMathReady = resolve);
window.MathJax = {
  "tex": {
    "inlineMath": [
      [
        "\\(",
        "\\)"
      ]
    ],
    "tags": "none",
    "tagSide": "right",
    "tagIndent": ".8em",
    "packages": {
      "[+]": [
        "base",
        "extpfeil",
        "ams",
        "amscd",
        "color",
        "newcommand",
        "knowl"
      ]
    }
  },
  "options": {
    "ignoreHtmlClass": "tex2jax_ignore|ignore-math",
    "processHtmlClass": "process-math"
  },
  "chtml": {
    "scale": 0.98,
    "mtextInheritFont": true
  },
  "loader": {
    "load": [
      "input/asciimath",
      "[tex]/extpfeil",
      "[tex]/amscd",
      "[tex]/color",
      "[tex]/newcommand",
      "[pretext]/mathjaxknowl3.js"
    ],
    "paths": {
      "pretext": "https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/lib"
    }
  },
  "startup": {
    pageReady() {
      return MathJax.startup.defaultPageReady().then(function () {
      console.log("in ready function");
      rsMathReady();
      }
    )}
  }
};
</script><script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js"></script><meta xmlns:xlink="http://www.w3.org/1999/xlink" name="Keywords" content="Authored in PreTeXt">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta xmlns:xlink="http://www.w3.org/1999/xlink" property="og:type" content="article">
<script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/lib/jquery.min.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/lib/jquery.sticky.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/lib/jquery.espy.min.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/pretext.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/pretext_add_on.js?x=1"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/user_preferences.js"></script><!--** eBookCongig is necessary to configure interactive       **-->
<!--** Runestone components to run locally in reader's browser **-->
<!--** No external communication:                              **-->
<!--**     log level is 0, Runestone Services are disabled     **-->
<script type="text/javascript">
eBookConfig = {};
eBookConfig.useRunestoneServices = false;
eBookConfig.host = 'http://127.0.0.1:8000';
eBookConfig.course = 'PTX_Course_Title_Here';
eBookConfig.basecourse = 'PTX_Base_Course';
eBookConfig.isLoggedIn = false;
eBookConfig.email = '';
eBookConfig.isInstructor = false;
eBookConfig.logLevel = 0;
eBookConfig.username = '';
eBookConfig.readings = null;
eBookConfig.activities = null;
eBookConfig.downloadsEnabled = false;
eBookConfig.allow_pairs = false;
eBookConfig.enableScratchAC = false;
eBookConfig.build_info = "";
eBookConfig.python3 = null;
eBookConfig.runestone_version = '7.5.15';
eBookConfig.jobehost = '';
eBookConfig.proxyuri_runs = '';
eBookConfig.proxyuri_files = '';
eBookConfig.enable_chatcodes =  false;
</script>
<!--*** Runestone Services ***-->
<script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/prefix-runtime.a0c870bab402ccbf.bundle.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/prefix-723.3e6434f80549315a.bundle.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/prefix-runestone.f6bda0c0ccce4835.bundle.js"></script><link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/prefix-723.3bccd435914aa0ff.css">
<link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/prefix-runestone.97de40e034b535c5.css">
<script xmlns:xlink="http://www.w3.org/1999/xlink" src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/lti_iframe_resizer.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/lunr.js/2.3.9/lunr.min.js" integrity="sha512-4xUl/d6D6THrAnXAwGajXkoWaeMNwEKK4iNfq5DotEbLPAfk6FSxSP3ydNxqDgCw1c/0Z1Jg6L8h2j+++9BZmg==" crossorigin="anonymous" referrerpolicy="no-referrer"></script><script src="lunr-pretext-search-index.js" async=""></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/pretext_search.js"></script><script src="https://cdn.jsdelivr.net/gh/PreTeXtBook/html-static@2.16/dist/_static/pretext/js/lib/knowl.js"></script><!--knowl.js code controls Sage Cells within knowls--><script>sagecellEvalName='Evaluate (Sage)';
</script>
</head>
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\newcommand{\lt}{&lt;}
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\definecolor{fillinmathshade}{gray}{0.9}
\newcommand{\fillinmath}[1]{\mathchoice{\colorbox{fillinmathshade}{$\displaystyle     \phantom{\,#1\,}$}}{\colorbox{fillinmathshade}{$\textstyle        \phantom{\,#1\,}$}}{\colorbox{fillinmathshade}{$\scriptstyle      \phantom{\,#1\,}$}}{\colorbox{fillinmathshade}{$\scriptscriptstyle\phantom{\,#1\,}$}}}
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<main class="ptx-main"><div id="ptx-content" class="ptx-content"><section xmlns:xlink="http://www.w3.org/1999/xlink" class="article" id="Counting-Colorings-Recursion"><section class="worksheet" id="ws-Counting-Colorings-Recursion"><h2 class="heading hide-type">
<span class="type">Worksheet</span><span class="space"> </span><span class="codenumber">1</span><span class="space"> </span><span class="title">Counting Colorings with Recursion</span><div class="print-links">
<a href="ws-Counting-Colorings-Recursion-a4.html" class="a4">A4</a><a href="ws-Counting-Colorings-Recursion-letter.html" class="us">US</a>
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</h2>
<section class="onepage" id="ws-Counting-Colorings-Recursion-2"><div class="introduction" id="ws-Counting-Colorings-Recursion-2-1"><div class="para" id="ws-Counting-Colorings-Recursion-2-1-1">Consider two ways to make a graph smaller: you can remove edge <span class="process-math">\(e\)</span> from <span class="process-math">\(G\)</span> (we will call this <span class="process-math">\(G - e\)</span>), or you can <dfn class="terminology">contract</dfn> the edge <span class="process-math">\(e\text{,}\)</span> pulling its endpoints together to form one new vertex and removing <span class="process-math">\(e\)</span> (we will write this <span class="process-math">\(G/e\)</span>).</div></div>
<article class="exercise exercise-like" id="ws-Counting-Colorings-Recursion-2-2"><h3 class="heading"><span class="codenumber">1<span class="period">.</span></span></h3>
<div class="para" id="ws-Counting-Colorings-Recursion-2-2-1-1">To get a feel for these two operations, draw <span class="process-math">\(G-e\)</span> and <span class="process-math">\(G/e\)</span> for three different edges in the graph below.</div> <div class="image-box" style="width: 25%; margin-left: 37.5%; margin-right: 37.5%;"><svg xmlns="http://www.w3.org/2000/svg" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" version="1.1" viewBox="0 0 94 65" role="img" class="contained" aria-label="A labeled graph consisting of a 4-cycle and 3-cycle, sharing an edge"><title>A labeled graph consisting of a 4-cycle and 3-cycle, sharing an edge</title><defs>
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<div class="workspace" data-space="1in"></div></article><article class="exercise exercise-like" id="ws-Counting-Colorings-Recursion-2-3"><h3 class="heading"><span class="codenumber">2<span class="period">.</span></span></h3>
<div class="para" id="ws-Counting-Colorings-Recursion-2-3-1-1">For a fixed value of <span class="process-math">\(k\text{,}\)</span> which is larger: <span class="process-math">\(P(G,k)\)</span> or <span class="process-math">\(P(G-e,k)\text{?}\)</span> How does <span class="process-math">\(P(G/e,k)\)</span> compare with <span class="process-math">\(P(G,k)\text{?}\)</span>
</div>
<div class="workspace" data-space=".5in"></div></article><article class="exercise exercise-like" id="ws-Counting-Colorings-Recursion-2-4"><h3 class="heading"><span class="codenumber">3<span class="period">.</span></span></h3>
<div class="para" id="ws-Counting-Colorings-Recursion-2-4-1-1">Prove that for any fixed edge <span class="process-math">\(e\text{,}\)</span> <span class="process-math">\(P(G-e,k) = P(G,k) + P(G/e,k).\)</span>
</div>
<div class="workspace" data-space="1in"></div></article><article class="exercise exercise-like" id="ws-Counting-Colorings-Recursion-2-5"><h3 class="heading"><span class="codenumber">4<span class="period">.</span></span></h3>
<div class="para" id="ws-Counting-Colorings-Recursion-2-5-1">We can rearrange this to be a useful recurrence: <span class="process-math">\(P(G,k) = P(G-e,k) - P(G/e,k)\text{.}\)</span> Use this to find <span class="process-math">\(P(C_4,k)\)</span> and then <span class="process-math">\(P(C_5,k)\text{.}\)</span>
</div>
<div class="workspace" data-space="1.5in"></div></article></section><section class="onepage" id="ws-Counting-Colorings-Recursion-3"><article class="exercise exercise-like" id="ws-Counting-Colorings-Recursion-3-1"><h3 class="heading"><span class="codenumber">5<span class="period">.</span></span></h3>
<div class="para" id="ws-Counting-Colorings-Recursion-3-1-1-1">Prove that <span class="process-math">\(P(C_n, k) = (k-1)^n + (-1)^n(k-1)\)</span> for <span class="process-math">\(n \ge 3\text{.}\)</span>  (What proof technique would be useful here, given that we have a recurrence relation?)</div>
<div class="workspace" data-space="3in"></div></article><article class="exercise exercise-like" id="ws-Counting-Colorings-Recursion-3-2"><h3 class="heading"><span class="codenumber">6<span class="period">.</span></span></h3>
<div class="para" id="ws-Counting-Colorings-Recursion-3-2-1-1">Use the recurrence relation (which is called the <em class="emphasis">deletion/contraction recurrence</em>) to find the <span class="process-math">\(P(G, k)\)</span> for our first graph:</div> <div class="image-box" style="width: 25%; margin-left: 37.5%; margin-right: 37.5%;"><svg xmlns="http://www.w3.org/2000/svg" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" version="1.1" viewBox="0 0 94 65" role="img" class="contained" aria-label="A labeled graph consisting of a 4-cycle and 3-cycle, sharing an edge"><title>A labeled graph consisting of a 4-cycle and 3-cycle, sharing an edge</title><defs>
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dbrace

Thank you for clarifying, @OscarLevin, and for the examples.

Based on what...

@Gabriel33 said
@Gabriel33 linked to from a few days at Re: Issue displaying HTML file in Modules – Blank ... - Instructure Community - 639683
@chriscas said as a reply at the link above (please see the screenshot)

... there is nothing that we are able to do (even though it was previously working, it was technically not supported) and you would need to report this to Canvas Support.

-Doug

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