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.
You cannot migrate the full workflow history and page status to Cloud. Only the last workflow state is included in the Atlassian migration data. If your organization is in a Compliance/Regulatory industry and you periodically get audited, then you will be required to keep Confluence on a server in read-only mode so auditors can review your previous Workflow History/page activity and/or Page Status. From Comala Document Management v6.18.0 or later, the workflow history can also be added to each page in a space in your server instance using the space tools document management Attach Activity option prior to migration. Attach Activity completion is checked for each space during the pre-migration checks and the affected spaces (with no Attach History - status is not set as COMPLETED) are listed and listed in a downloadable CSV file.Maintaining auditable history
Also, if your destination Cloud site has existing data, create a site backup before importing your space(s).
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