High Sierra Public Beta - Cannot Boot - Error Loading Kernel Cache

Hello all -


I'm running a 27" iMac (late 2013) with a 3.5 GHz Intel Core i7, 16GB RAM and 3TB fusion drive, and Sierra 10.12.6 Beta.


Several times, I've attempted to install the High Sierra Public Beta (both released versions) on an external USB 1TB disk (normal Seagate drive), and the install goes fine until a boot is attempted from the external drive.


In every case, I get a "0" icon at boot, which indicates that a valid system folder cannot be found. Watching the screen in "verbose" boot mode, I get "Error loading kernel cache (0xe)"


I've tried re-downloading the installer, doing a command-line installer from the terminal, creating a regular Sierra OS external disk and tried to upgrade that to High Sierra, and no joy.


Is this problem something inherent with my iMac configuration, or has anyone succesfully installed High Sierra on this kind of machine?


Thanks!

Update: Thinking that resources are possibly copied from the existing version of Sierra (which was 10.12.6 in my case), I downgraded to Sierra 10.12.5 (the latest current release), and restarted the process from scratch (including reformatting the target High Sierra disk). Result: no change.


I'm guessing there is something inherent in the late 2013 iMac configuration that simply does not play nice with the current High Sierra beta.

High Sierra Public Beta - Cannot Boot - Error Loading Kernel Cache
 
 
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