Overview:
The CRF import fails, for no apparent reason, even though the file was only created as a ZIP.
Root Cause:
CRF import ZIP requirements detail the ZIP file structure required. This can be overlooked on Macs where zip files do not have a top-level folder. The user who is creating the zip file needs to create a top-level folder that contains the site-specific folders. Then, zip the top-level folder.
Solution:
On a MAC, after the file is zipped, run:
zipinfo {zip_file_name}

Note: The entries in the zip file do not have a top-level folder. It is {site_id} / {document_name}
It should appear as shown:

Note: The entries in the zip file have the format of topLevelDirectory/{site_id} / {document_name}
Related Documentation:
Vault Help Documentation: