This is a bug which makes the UUID unreadable in the /etc/crypttab and accordingly no swap will be read and used by the system, which is unacceptable of course.

In order to solve this problem, all you have to do is the following:

1. Determine which partition is your swap partition: “sudo fdisk -l”, check the line that looks like this:
   /dev/sda6       617330688   625141759     3905536   82  Linux swap / Solariswhich means that “/dev/sda6” is your swap partition
2. Take a backup of your /etc/crypttab file: “sudo cp /etc/crypttab /etc/crypttab.orig”
3. Modify the /etc/crypttab file to replace the UUID with the old-style partition way, for example change from this:
   cryptswap1 UUID=32504c50-3336-42fa-813f-f412050ce2f7 /dev/urandom swap,cipher=aes-cbc-essiv:sha256
   to this:
   cryptswap1 /dev/sda6 /dev/urandom swap,cipher=aes-cbc-essiv:sha256
4. Save the file and restart
5. Enjoy! 🙂

Source: http://ubuntuforums.org/showthread.php?t=2221067