Description
One possible cause is an incorrectly configured override for this attribute. For example, a Display by Ref override has been created for multiple table columns.
Workaround
Only one Display by Ref override can be created for a table (Table override field). After removing unnecessary overrides, reset the server cache by running the following script in the browser console:
javascript: window.open(`/v1/settings/flush-cache?access-token=${s_user.accessToken}`);
Theory:
When the Display By Ref attribute is activated, it is automatically deactivated for other table columns. The column for which Display By Ref is deactivated may become read-only, making it impossible to revert to the out-of-the-box version.
To set Display by Ref for a custom field without affecting other columns, use Column Override. For example, for the Incident table, you want to display the custom column Short information [c_short_info]. By default, the Displayable name field inherited from the Task table is displayed for incidents. If you activate Display by Ref for the Short information column, the display field will be configured only for incidents. On other tables—Task, ITSM Task, Problem, etc.—Display by Ref will remain inactive.
To resolve this issue, create an override record with the following values:
Base Table: Incident
Table: Incident
Column: Short information
Display by Ref Override: Yes