Edited Unassigned: open old project on VS 2013 error when update NTVS 1.0 RC2 [1786]

E:\MEAN\Poll\VoteOnline\VoteOnline.njsproj : error : The project file 'E:\MEAN\Poll\VoteOnline\VoteOnline.njsproj' cannot be opened.

There is a missing project subtype.
Subtype: '{3AF33F2E-1136-4D97-BBB7-1795711AC8B8}' is unsupported by this installation.