Description of problem: After installing F20 beta TC6 to a Toshiba laptop (Satellite P50-A) via live image, grub comes up offers to boot the linux kernel. However, after selecting the kernel, it says Bootloader has not verified loaded image. System is compromised. halting. and then it powers down. The one strange bit during the install was that it did not automatically recognize the system's existing EFI partition (/dev/sda2, used by windows), and instead wanted to create a new one. I manually directed it to use sda2 (deleted the one it wanted to create and told it to mount /dev/sda2 as /boot/efi, but to not format it). The install recognized windows being already installed and added that as another boot option in grub. Selecting that allows windows to boot happily.
After a BIOS update and installing F20, the system boots fine.