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The 3DEXPERIENCE platform does not support recovered elements. Thus, you cannot remove used projects while keeping the references. You only have the option to remove a used project together with its references, as shown below:
Removing a used project.
I cannot open a project that uses other projects and see a message that a used project is missing. Why?
If you do not have access to a used project or it is deleted, you cannot open the main project. You must have access to all content that is used in the main project.
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