[Koha] Importing Marc records from Koha 2.2.9 into 3.14.05

Hello! I have been unsuccessfully trying to export records from Koha 2.2.9 by going to Marc Biblio Export; selecting a call number range, clicking export and saving the file in notepad (not sure what program to use). The resulting file has a .mrc extension so I am presuming it is a Marc file, there is also data there. However, when I try to import it into version 3.14.05 it isn't being recognised. The steps I am following in version 3.14.05 are as follows: * Stage MARC records for Import * Select the file (koha.mrc) * Upload file The screen then briefly flashes 0% loading and then disappears. In Staged MARC management there is then no data. Any thoughts?? Thanks Liz