Complex sentence: The Vault has yet to air pre- 1990 editions of the show or editions from 1993-1995 as said episodes were (and still are to this day) stored on unplayable formats, and the network does not have compatible machines equipped to play the episodes.
Split into simpler sentences: The Vault has yet to air pre- 1990 editions of the show or editions from 1993-1995. This is because the episodes are stored on unplayable formats, and the network does not have compatible machines equipped to play the episodes.