Symptom
Extension field of type Formatted Text cannot be used on Services and you get the following warning message: Properties of this field cannot be maintained.
Environment
SAP Cloud for Customer
Cause
Extension field of type Formatted Text cannot be used in other scenarios and services.
Resolution
This feature is not supported in the current release of SAP Cloud for Customer.
If the feature/functionality is required urgently, please refer to KBA 3475641 - Functionality Currently not Available.
An alternative option may be to check the corresponding SAP Customer Influence Site to submit an idea:
Keywords
Field Properties Cannot be Maintained, Formatted Text field, extension field , KBA , AP-RC-UIF-FLX , Page Layout & Key User Configuration , AP-RC-UIF , C4C UI Framework , How To