The solution describe here (http://zeroset.mnim.org/2015/05/10/ubuntu-15-04-vivid-vervet-please-enter-passphrase-for-disk-cryptswap1-on-none/) which uses the device path instead of the UUID made it work for me.
The solution describe here (http:// zeroset. mnim.org/ 2015/05/ 10/ubuntu- 15-04-vivid- vervet- please- enter-passphras e-for-disk- cryptswap1- on-none/) which uses the device path instead of the UUID made it work for me.