After some investigation I found the following symptoms and error messages:
- There were some scree rendering issues / I could mouse the mouse but not click or type.
- I was able to use Remote Desktop / VNC to connect and interact with the computer properly.
- In Activity Monitor the kernel_task process was using 100% of the CPU on one of the cores.
- I could boot to Windows at startup and had no problems, errors, or lag there.
Could not find IODeviceTree:/options EFI found at IODeviceTree:/efi Mount point for /Volumes/BOOTCAMP is /Volumes/BOOTCAMP flushing fs disk buffer returned 0x5 IOHIDSystem: postEvent LLEventQueue overflow. Can't access "efi-boot-device" NVRAM variable no bootx creation request nvram: nvram is not supported on this system
One of the messages when I was testing the Unix bless command indicated that the "efi-boot-device" NVRAM variable was not accessible. I then tried to examine it with the Unix nvram command only to get the "nvram: nvram is not supported on this system" error. I found the NVRAM error very odd And was surprised the computer was even booting if the nvram was defective. I then tried to reset the NVRAM as it was not operating properly.
As it turned out the problem all along was that the NVRAM had corrupted and was non-functional. I did a hard reset of the NVRAM and all the problems went away immediately. To reset the NVRAM you just reboot and hold down Command, Option, P, and R as the computer boots, or see this Apple Document.