As more and more people are stuck with this bug and don't know what to do, here's a small how I fixed it:
1. Download SuperGrubDisk2 Beta: http://www.supergrubdisk.org/category/download/supergrub2diskdownload/super-grub2-disk-beta/
2. Burn it to CD or put it on USB stick
3. Restart and choose the CD/USB as boot device
4. Boot manually into your Ubuntu from the Super Grub Disk menu
5. In Ubuntu run "Disk" or "Gparted" and determine your boot partition (e.g. like /dev/sda1)
6. Open Terminal and reinstall grub on the boot device (meaning leave out the partition number): "sudo grub-install --recheck /dev/sda"
With this grub is reinstalled and all installed OS are detected properly setup in grub.
As more and more people are stuck with this bug and don't know what to do, here's a small how I fixed it:
1. Download SuperGrubDisk2 Beta: http:// www.supergrubdi sk.org/ category/ download/ supergrub2diskd ownload/ super-grub2- disk-beta/
2. Burn it to CD or put it on USB stick
3. Restart and choose the CD/USB as boot device
4. Boot manually into your Ubuntu from the Super Grub Disk menu
5. In Ubuntu run "Disk" or "Gparted" and determine your boot partition (e.g. like /dev/sda1)
6. Open Terminal and reinstall grub on the boot device (meaning leave out the partition number): "sudo grub-install --recheck /dev/sda"
With this grub is reinstalled and all installed OS are detected properly setup in grub.