Why won't my imac read a dvd that it has just burned in a samsung external dvd.
I am haveing major problems with the dvd writer in my iMac (20-inch, Early 2008) . Since upgrading to Yosemite it will not play dvds that were burned on it previously. Purchased an external Samsung DVD burner and burnt a dvd. When I re inserted it into the external drive imac will not recognise the disc . It plays in a PC and on a DVD player. Any suggestions welcome