The Issue: Upon successful installation, boot from hard drive results in this: Loading Operating System … boot0: GPT boot0: test boot0: test boot0: GPT boot0: test boot0: test boot0: error The Actual Problem: With disk drives getting larger and larger manufacturers have had to change the default block size from 512 bytes to 4,096 bytes. These new drives are known as "Advanced Format" or 4K drives. Initially this was only seen on drives larger than 1 TB but will soon be on all drives. As part of this change there is an issue with OS X writing the boot helper code to these drives when booted from the drive. Because of this they require a workaround to boot on their own. Solution 1: Use UniBeast Pros: Easy- OS X Only Cons: Requires use of the Terminal and UniBeast drive. How To Do it: 1. Install using UniBeast 2. Boot new installation using UniBeast created USB. 3. Run MultiBeast and install as normal 4. Reboot system back into OS X installer. 5. Run Disk Utility and unmount the drive you installed OS X on. Right click on the volume and select Unmount. 6. Launch Terminal and execute the following command: Code (Text): dd if=/usr/standalone/i386/boot1h of=/dev/disk0s2 7. Exit Terminal 8. Reboot Normally NOTE: The above instructions are based on OS X being installed to a hard drive connected to SATA port 0. If you are using a different port you will need to get the drive device name from Disk Utility by selecting the volume and clicking Info. Solution 2: Use a SATA > USB Adapter Pros: Easy- OS X Only Cons: Need an additional functional Mac or Hack. How To Do it: 1. Install using UniBeast using System 1. 2. After installation, shut down, unplug the SATA drive from System 1, and plug into System 2 via USB 3. Boot System 2 4. Run MultiBeast, targeting System 1's drive 5. Unplug the System 1 drive, plug back into System 1, and boot without any issues. SATA/PATA/IDE Drive to USB 2.0 Adapter Converter Cable with AC Power Adapter for 2.5 / 3.5 Inch Hard Drive / Optical Drive http://www.amazon.com/gp/product/B001OORMVQ/ref=as_li_ss_tl?ie=UTF8 [amazon-uk]http://www.amazon.co.uk/gp/product/B001OORMVQ/ref=as_li_ss_tl?ie=UTF8[/amazon-uk] An extremely useful extra for any custom build. Hook a hard drive up to another working system via USB. Also use to convert a internal optical drive into an external USB optical drive.