I have a Nexus 7 2013 which I'm trying to flash the Android Lollipop preview image to. It's currently running the last Android L preview image.
Whenever I boot the device to the bootloader screen while it is attached via USB to my computer (mac), the device freezes and adb doesn't recognise it. Booting to the bootloader using power button + volume down works normally. I can start flashing the image with the flash-all.sh script, but when the script tries to reboot the device to bootloader I run into this crash and the flashing halts.
How can I get around this problem?