You need to ensure that the user who runs the migration has at the very least the following permissions
Server instance
has system administrator permission on the server instance
Cloud site
user exists in the target Cloud site
and has site administrator permission
Administrator permission must include space administrator permission for each destination space.
Page-level restrictions may prevent the successful migration of a page. These may need to be removed before migration. All pages with a page-level restriction and a workflow history are reported in the Atlassian Migration Assistant pre-migration vendor checks.
