A migration can cause errors - ensure that you have a secure backup of your Confluence server instance. You should also run the server instance in read-only mode during the migration.
You might like to look at the Atlassian Cloud Migration Resources - in particular the Atlassian Confluence Pre-Migration Checklist.Insert excerpt
| Info |
|---|
Also, if your destination Cloud site has existing data, create a site backup before importing your space(s). |
