problem

JS Error when trying to edit a segment when all editable columns in the grid are disabled.

reproduction

1. Open a task
2. Disable all editable (target and source if editable) content columns
3. Double click the segment

JS Error:

Uncaught TypeError: Cannot read property 'replace' of undefined
at constructor.markup (HtmlEditor.js?_dc=1600188090410:364)
at constructor.markupForEditor (HtmlEditor.js?_dc=1600188090410:267)

possible solution

Just fix it in a way, so that no error happens anymore.

First thought was to disable row editing, but perhaps the user only wants to set QM or states in the metapanel, then the segment should be editable.

Also a pop-up should be implemented, that shows a message to the user, that all editable colums are hidden, if he opens a task for editing and this is the case.
DE: Alle editierbaren Spalten sind versteckt. Klicken Sie auf den Pfeil im Kopf einer Spalte, um versteckte editierbare Spalten einzublenden.
EN: All editable columns are hidden. Click on the arrow in the header of a column to show hidden editable columns.