TypeError: Cannot read properties of undefined (reading 'childNodes') occurs sometimes in course.js

[empty-codes]

What is happening?

TypeError: Cannot read properties of undefined (reading 'childNodes') occurs sometimes in course.js when initializing a List object.

WikiEduDashboard/app/assets/javascripts/utils/course.js

Line 72 in 7dc281e

studentsList = new List('users', {

Relevant Stack Trace:

TypeError: Cannot read properties of undefined (reading 'childNodes')
at this.getItemSource(./node_modules/list.js/src/templater.js:37:29)
at Templater(./node_modules/list.js/src/templater.js:6:28)
at module.exports(./node_modules/list.js/src/templater.js:173:10)
at init.start(./node_modules/list.js/src/index.js:53:27)
at module.exports(./node_modules/list.js/src/index.js:261:8)
at document.onreadystatechange(./app/assets/javascripts/utils/course.js:72:20)

Expected behavior

Error should not occur.

Additional context

The exact course of the error is not known so your first step should be trying to reproduce the error.

From my research, it might be caused by the #users table not being fully loaded / rendered / has missing elements / wrong structure. I added isTableValid('#users') in this commit to check if the table exists before calling new List(...) but that did not fix the error.