When copying Multichannel Presentation and Slides to another Vault, an error occurs: OPERATION_NOT_ALLOWED cause: Unable to checkout [placeholder] document
This is expected behavior. The target document contains a placeholder.
Placeholders are not able to be checked out of Vault.
The user is required to upload content to the placeholder or remove the placeholder Multichannel Slide document.
Vault to Vault Migration Documentation: Copy to Another Vault