mac wont start after installing el capitan

I've had the very same experience with my Mac Pro as soon as I migrated any programs/data to El Capitan it would no longer boot.

I wasted several days trying to get it to work and couldn't.

I reinstalled Yosemite and haven't looked back.

DO NOT TRY TO MIGRATE PHOTOS Library to El Capitan until you've backed the old file up separately to another drive or time machine.

Once you migrate them to El Capitan, they NO LONGER WORK under Yosemite.

For everyone else who's gotten it to work, Congrats.

My Mac Pro runs it fine, but IT WONT BOOT after adding my actual programs/data/startup files that work fine under 10.10.5 Yosemite.

Startup - Gray, Blue or White screen at boot, w/spinner/progress bar

Startup Issues - Resolve

Startup Issues - Resolve (2)

Startup Issues - Resolve (3)

I have a 2009 Mac Pro with this problem. The best solution is Link Davis' 14-step solution. I did all of the steps until step 12 finally fixed it. You will need a Time Machine Backup. If you have one, you're good. If not, you will need to make one. If you get to step 12 and you don't have a Time Machine backup, you can get your computer back temporarily on by using Carlos's "touch" trick in Terminal:Re: El Capitan won't Boot after update(I did this too, which will work, but after shutting down, my computer went back to not being able to fully start up again.)

To get my mac back to normal, I had to then do a Time Machine backup and then complete step 12. I can now shut down and restart with no issues using 10.11.1.

I HAVE FIXED THIS PROBLEM FOR EVERYONE!

After all the WRONG information on the entire website... its SO SIMPLE.

UNPLUG YOUR USB, YOUR FIREWIRE from the back of your IMAC27 and it will boot.

THE UPDATES DO NOT WORK WITH MY PEGASUS DRIVES or my TANGENT DEVICES off the USB.

if your using a USB HUB.... take it out of the back!

it WILL WORK.

they must only test their updates with the RAW COMPUTERS and no connections.

now you know!

chris maynard

cmiVFX.com