The snapshot log in a dump file is imported if the master table already exists for the database to which you are importing and it has a snapshot log.
When a ROWID snapshot log is exported, ROWIDs stored in the snapshot log have no meaning upon import. As a result, each ROWID snapshot's first attempt to do a fast refresh fails, generating an error indicating that a complete refresh is required.
To avoid the refresh error, do a complete refresh after importing a ROWID snapshot log. After you have done a complete refresh, subsequent fast refreshes will work properly. In contrast, when a primary key snapshot log is exported, the values of the primary keys do retain their meaning upon import. Therefore, primary key snapshots can do a fast refresh after the import.
Oracle Database Advanced Replication for Import-specific information about migration and compatibility and for more information about snapshots and snapshot logs