Why am I unable to alter the Entry Type for a Message Base?
Message Bases, Oracle B2C Service
The Entry Type is chosen when a message base is created. Once it is saved, the Entity Type can no longer be modified due to the framework specified for each of these Entry Types (plain, HTML, hot key attributes).
For additional information, refer to the Create a Custom Message Base Entry section in online documentation for the version your site is currently running. To access Oracle B2C Service manuals and documentation online, refer to the Documentation for Oracle B2C Service Products.