I reproduced this bug by adding an additional menuentry in file '/etc/grub.d/40_custom'.
Previous version of the file (no bug): #!/bin/sh exec tail -n +3 $0 # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. New version of the file, producing the bug: #!/bin/sh exec tail -n +3 $0 # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. menuentry ‘Windows 10 msdos2′ { set root='(hd0,msdos2)’ chainloader +1 } Finally, I solved the bug by creating a new file '/etc/grub.d/42_custom' and put the new menuentry there... Hope this helps. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/775377 Title: grub-mount assert failure: *** glibc detected *** grub-mount: free(): invalid next size (fast): 0x08d25b98 *** To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/775377/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs