Also be sure that you’re not referencing other assets (smart lists, forms, emails, landing pages) that aren‘t accessible in the other workspace. Smart lists and snippets, like template, can be shared. Emails, LPs, and forms cannot - and will need to reside locally within the program you’re cloning.
I think the issue here is that the templates used in the assets are not available in the other Workspaces, you have to also Share the templates across the Workspaces so you can clone assets.
The steps are:
In your Global Workspace, go to Design Studio, then in Landing Pages, create a folder under templates, name it Shared Templates, drag in all the templates you want to share, then right click and Share Folder and select your other Workspaces.
Do the same steps for Email Templates.
Once this is complete, try Cloning the original template and you should get no errors. Please note the error message is a bit misleading, as it doesn't actually mean that the assets are being used somewhere but more that the templates don't exist.
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