Symptom: com.atlassian.confluence.importexport.ImportExportException: The zip doesn't contain an 'entities.xml' file in it.

When backup files are zipped on Windows backslash is used as the path separator. These backslashes then cause Unix boxes to be unable to find files in the zip.

Backups created on Unix import into Windows with no problems.

Workaround: Unzip the backup file and re-create it with a tool that stores path separators as forward-slashes (the Linux command-line zip tools can do this)