About Migrating to the Enhanced Semantic Model Extension Framework

Prior to switching over to the new semantic model extensions framework, do note these and take appropriate action where required:

Before migration, merge all your changes to the main branch and publish it because Oracle will migrate the current main branch, but not the custom branches.
Security configurations will remain unchanged in the new framework, hence no action from you is required.
Upgrade all non-production and production instances to the new framework before attempting any migration of semantic extensions from non-production to production instances using the Bundles functionality.

You can initiate migration of your extensions to the enhanced framework by submitting the request from the banner message on the Semantic Model Extensions page when you click User Extensions. You can initiate it automatically by scheduling the migration from the banner message. After initiating the migration:

You can't use the semantic model extensions capability during the migration process.
Oracle migrates the existing customizations to the new framework. Once the migration is complete, you receive a notification on the console. You can also monitor the status in the Activity tab for Semantic Model Extensions.
Sign in and sign out of your service after migration completes.
Once the migration is completed, you see a downloadable report that shows which customizations are available for which object with the Main branch object to Main sandbox object mapping (so that you can see all your customizations that have been brought over). In most cases, operations like Add Dim, Add Fact, Add Variable, Extend Dimension, Add Columns have 1:1 correspondence between the old and the new framework. The Main sandbox is published and ready for use. All of your subject areas, visualizations, and reports remain unchanged. An option to revert to the old framework if customizations aren't as expected is available and the migration rollback option gets disabled after 60 days from the migration date. Ensure to complete the reversal process within this period, if you must revert. If you choose to revert, then the semantic model reverts to the state prior to the migration being initiated. You can't rollback the migration if you've completed a content upgrade after completion of the migration process.
Oracle maintains a backup of the existing semantic model extensions at the time the migration is initiated. If you encounter issues during or after migration, Oracle uses the backup to troubleshoot and enable required extensions on the new framework. Should you choose to revert back to the previous state, the semantic model is restored from this backup. If you've made further changes to the semantic model in the new framework before choosing to revert, these customizations can't be migrated to the previous semantic model extensions framework.