Background

If a custom page and its container have references to different spaces, XML space export would generate a backup file with 2 spaces inside. As a result, XML import will try to import two spaces and fail because the second space would already exist in the DB.
The typical error message is "could not execute statement".

Here is the link to the root cause bug: https://jira.atlassian.com/browse/CONFSERVER-77826

Note: this bug relates to XML backup/restore functionality only. It will be closed when XML backup will not export unnecessary spaces anymore (no matter whether the database has inconsistencies or not).

Expected behaviour

XML backup does not contain unnecessary space.

Workaround

The workaround is described here: https://jira.atlassian.com/browse/CONFSERVER-77826