While importing a backuped space an error message with no description pops up, what has gone wrong?

Question

The following error shows after the attempt to upload the .zip file:

Dan Tombs · Answer

Hi @Administrator With cases like this you may want to look to Atlassian support or at least the audit log to see if there was any additional information as to why it failed.

If all the files aren't corrupt and are in the right formats etc. then I think this may be your only route.

Administrator · Answer

Thank you but unfortunately this doesn't help, as my backup file is in the correct (.zip) format including all the exportDescriptor.properties, entities.xml and attachments folder (all together zipped 15 989 940 KB)... 
With another space it was working but this one shows this error.

Sayed Bares [ServiceRocket] · Answer

@Administrator you may want to check out this community thread which answers your question:

* https://community.atlassian.com/t5/Confluence-questions/Import-confluence-space-from-cloud-export-fails-with-an-error/qaq-p/1657449