I had this very problem the 1st few days of working with X3.
(also broke my v-vocal)
What fixed my system, was an odd sequence of trying (comparing) Melodyne 2.1.1
and Sonar`s X3 essentials version.
1st. Deactivating Melodyne2.1.1.
2nd. Trying Sonar essentials, another re-license moment
going thru the licensing at Melodyne
3rd. Then deactivating X3`s Melodyne essentials,
4th. Then re-activiting 2.1.1 Melodyne again.
(repete as necesary?)
I may have done this a few tries, It`s works now for me
Both v-vocal and Melodyne 2.1.1 are running fine for me.
I use both in every project, but with the lastest Melodyne integration,
I probably be using a lot less of v-vocal.
This Fixed my X2 v-vocal crashing also.
Good luck,
Don Belisle
Q6600, i7, i5, 8 gigs mem typ, X3b, Motu MKIII, other goodies