#upstream [[ https://issues.jenkins.io/browse/JENKINS-70906 | issue JENKINS-70906 ]], [[ https://github.com/jenkinsci/jenkins/pull/7781 | pull ]], https://www.jenkins.io/blog/2023/05/12/removing-prototype-from-jenkins/
When browsing a job that has collapsible sections recognized in Jenkins ( ex: https://integration.wikimedia.org/ci/job/mediawiki-quibble-selenium-vendor-mysql-php74/lastSuccessfulBuild/console ), the table of content no more shows up in the sidebar.
There is a JavaScript error in the console:
```
name=behavior.js:120:27,counterexample,lines=8
11:45:52.851 ReferenceError: Ajax is not defined
loadOutline https://integration.wikimedia.org/ci/static/ffdb6c1a/descriptor/org.jvnet.hudson.plugins.collapsingconsolesections.CollapsingSectionNote/script.js:79
handle https://integration.wikimedia.org/ci/static/ffdb6c1a/descriptor/org.jvnet.hudson.plugins.collapsingconsolesections.CollapsingSectionNote/script.js:131
section https://integration.wikimedia.org/ci/static/ffdb6c1a/descriptor/org.jvnet.hudson.plugins.collapsingconsolesections.CollapsingSectionNote/script.js:154
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:117
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:111
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:109
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:107
apply https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:90
start https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:85
onload https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:152
onload https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:152
onload https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:152
addLoadEvent https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:151
<anonymous> https://integration.wikimedia.org/ci/static/ffdb6c1a/extensionList/hudson.console.ConsoleAnnotatorFactory/hudson.plugins.timestamper.annotator.TimestampAnnotatorFactory3/script.js:198
<anonymous> https://integration.wikimedia.org/ci/static/ffdb6c1a/extensionList/hudson.console.ConsoleAnnotatorFactory/hudson.plugins.timestamper.annotator.TimestampAnnotatorFactory3/script.js:201
behavior.js:120:27
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:120
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:111
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:109
applySubtree https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:107
apply https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:90
start https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:85
onload https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:152
onload https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:152
onload https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:152
(Async: EventHandlerNonNull)
addLoadEvent https://integration.wikimedia.org/ci/static/ffdb6c1a/scripts/behavior.js:151
<anonymous> https://integration.wikimedia.org/ci/static/ffdb6c1a/extensionList/hudson.console.ConsoleAnnotatorFactory/hudson.plugins.timestamper.annotator.TimestampAnnotatorFactory3/script.js:198
<anonymous> https://integration.wikimedia.org/ci/static/ffdb6c1a/extensionList/hudson.console.ConsoleAnnotatorFactory/hudson.plugins.timestamper.annotator.TimestampAnnotatorFactory3/script.js:201
```
The issue is somewhere between Jenkins 2.426.2 and 2.440.2.
The plugin source code is at https://github.com/jenkinsci/collapsing-console-sections-plugin and surely it has:
```
lang=javascript,name=src/main/resources/org/jvnet/hudson/plugins/collapsingconsolesections/CollapsingSectionNote/script.js
function loadOutline() {
if (outline !== null) return false; // already loaded
if (!loading) {
loading = true;
vvvv
var u = new Ajax.Updater(document.getElementById("side-panel"),
^^^^
rootURL+"/descriptor/org.jvnet.hudson.plugins.collapsingconsolesections.CollapsingSectionNote/outline",
{insertion: Insertion.Bottom, onComplete: function() {
```