We have recently observed the following behavior:

A CM12 Admin cannot create an ISO DVD by using the in Task Sequence. The TS contains OS, APPs, Patches ext.
If the Admin wants to create an ISO DVD from this TS, it ends up with the following error: "The Create Task Sequence Media Wizard completed with errors". The creation fails only when there is  - at least - one application.

If there is no application, then the creation finishes as expected.

Cause: It seems that we are hitting an issue related to Insufficient rights in the RBAC (role-based access control) model.

Resolution: In order to resolve it, you need to go to the CM12 Administration > Security Scopes and grant on the user account that you are using, the 'All instances of the objects that are related to the assigned security roles' permissions [on the “Assigned security scopes and collections” section].

Additionally, it seems that this issue will be fixed in the upcoming SP1, so we have to wait a little bit and see if SP1 installation resolves it.