Compass 1.16.3 exports documents in JSON using strict mode which is described under MongoDB Extended JSON.

When importing JSON documents, Compass currently does not accept mongo shell JSON representations. Refer to the screenshot of the "Unexpected token O in JSON at position 69" error. This is the source JSON file that generated that error.

{"dateTest":{"$date":{"$numberLong":"1552262400000"}},"objectIdTest":ObjectId("5c29e881d45e71235f7ad302"),"nullTest":null}

{"dateTest":{"$date":{"$numberLong":"1552435200000"}},"objectIdTest":ObjectId("30a9a881d45e21235b7ad302"),"nullTest":null}

In order for Compass to be more useful, it should accept either strict mode or mongo shell mode JSON on import of JSON files.