Sorting any task list (Incidents, Changes, Problems, etc.) by any column while on IE11 breaks the list editing feature.
Steps to Reproduce
1- Open any instance while using IE11.
2- Open any task record list view.
4- Double-click an editable field. Notice that you can edit the field successfully.
5- Sort the list by clicking a field's name from the list's header. An error is thrown in Developer tools:
Unable to get property 'firstChild' of undefined or null reference
File: js_includes_list_edit_doctype.jsx, Line: 1219, Column: 1
6- Double-click an editable field. Notice that you can not edit the field, the edit popup will not appear.
The issue is not reproducible with Chrome and Edge browsers. A workaround is also to sort the list via condition builder (except embedded).
Related Problem: PRB1239502