After updating my Z97X-UD3H running 10.12.6 to Clover r4586 the system would hang on a black screen shortly after the Clover boot menu.
Luckily I stumbled across this post that says the OsxAptioFix3Drv-64.efi driver has been removed, and that AptioMemoryFix.efi should be installed as its replacement from now on.
I can’t remember if Clover deleted OsxAptioFix3Drv-64.efi for me or not, but after installing AptioMemoryFix.efi the system started working again. Success!
A quick but useful explanation of the various drivers64UEFI memory fixes can be found here