Mac Pro 4,1 Fails to Boot About 60% of the Time

[kingseamus]

I have an early 2009 Mac Pro 4,1 that is often booting to a black screen that hangs indefinitely until I manually restart. I'm running 10.11.6.

When I do successfully boot to desktop, this is preceded by a 15-45 second wait and then command lines in verbose mode.

Tried resetting PRAM and NVRAM but these resets didn't resolve the issue.

Some of the command lines preceding a successful boot to desktop:
A number of variations of "Sandbox: launchd(1) System Policy: deny(1) file-write-flags /private/var/run/dyld_shared)_cache_x86..."
Ten rows of "fInterfaceSnapshots is missing"

Additional info about my system:

• Flashed GTX 980 Ti from MacVidCards
• Main drive is a 1TB SSD with a Bootcamp partition for Windows
• An SSD occupying one of my PCIe slots

 

[P1LGRIM]

Not a Desktop Guide - Moved to Mac Pro.

You have come to the wrong place as this is a site dedicated to the installation of Apple operating systems onto non-Apple hardware. For assistance with your Mac you may well fare better at one of the many Apple support forums elsewhere.