IDENTITY_INSERT is set to OFF

Error:
Cannot insert explicit value for identity column in table 'XYZ' when IDENTITY_INSERT is set to OFF.

Solution:
If you work on ASP .Net vNext with MVC 6.0 and EF 7.0 beta, welcome to hell :-))
It's was kidding.

Solution 1 is add [DatabaseGenerated(DatabaseGeneratedOption.None)] annotation to your ID of your Table (class model)

Solution 2 is add below line to OnModelCreating override method of your DbContext
builder.Entity<XYZ>().Property(i => i.Id).GenerateValuesOnAdd(generateValues: false);