I am the Site Owner of Confluence. A vendor of mine has a Cloud Confluence Space we'd like to import into my Instance in the cloud.
He has gone into Administration > Content Tools > Selected Export (XML) and then given me the .zip file.
When I choose Import Space and select the .xml file, I receive the following generic Error:

I have already triaged several of the suggested potential issues, including:
1) This is a cloud to cloud import of a single space
2) User Group Conflicts should not exist due to merging capability for cloud to cloud
3) Space Names are not in conflict
4) Proper Access rights for Site Admin in place