You can continue the export but it may fail due to large amount of items in unrecognized format, encrypted, weren't indexed ...

You can continue the export but it may fail due to large amount of items in unrecognized format, encrypted, weren't indexed or partially indexed. To better estimate before the export, edit the search, select "Include items that have an unrecognized format, are encrypted, or weren't indexed for other reasons" and rerun the search.