Boot up after installing El Capitan

Boot OS X Recovery by holding ⌘ and r (two fingers) while you start your Mac. Choose "Reinstall Mac OS X". That ought to reinstall El Cap and not your previously installed OS. See how far you get.

I Was stuck at that point as well. I performed a shutdown and restart and it booted up fine. Might be worth a try.

I solved it once by going into Recovery Mode and disabling 3rd party Kexts using terminal. Couple of reboots later and the empty load bar has returned. I've tried several reboots and repaired the partition in Disk Utility. Still won't boot.

I don't recall reinstalling any new Kexts in the last 24 hours, but I'll repeat the process and hopefully it'll work again.

Full details here:

https://forums.developer.apple.com/message/67556#67556

see answer by Max108

I Really cannot solve this issue. I used recovery 3 times, re-install El Capitan, but when I reboot I get stucked on the grey screen with Apple logo and empty progress bar

I am having the same issue, after installing el capitan everything works fine till i reboot the system, then it gets stuck at Apple logo! :-(

i have reinstalled El captain 3 times already. installation works fine but again on rebooting its the same story. Really ****** off. planning to downgrade to yosemite.

MacBook Mid 2009

There is truly something wrong with this upgrade. Too many people (to include myself) continue to have this problem. I spent a couple of hours with Apple Support yesterday, and ended up with the same problem. The support person was very nice, but he can't compensate for a lousy operating system. Come on Apple, please try to get it together this time. Don't tell us that "we are holding it wrong", or some other crap. Just fix your software. Our checks and credit cards working, may be your products should also. I have downgraded back to Yosemite and will continue to use it until Apple gets it act together. Dell, Lenovo, Microsoft Surface?

Just a thought.

Unfortunately, I have to agree with 12David.

Mac Book Air of 2011.

Filevault active

Login freeze on 0% of progress bar after upgrade to El Capitan.

I am having the same issue! I have reinstalled El captain on my MacBook Pro (late 2008) 3 times.

The installation works fine but again on rebooting its the same story: login freeze on 0% of progress bar and Apple logo displayed. :-/

I will downgrade to Yosemite.

I have removed old kexts file left over from old installs of Eltima SyncMate and VirtualBox.

1. Booting up in recovery mode;
2. Open the terminal window and copy-paste the following commands into it (original post https://forums.developer.apple.com/message/39138#39138):

• rm -Rf /Library/Extensions/VBox*
• rm -Rf /Library/Application\ Support/VirtualBox/VBox*
• rm -Rf /System/Library/Extensions/Eltima*

After running these commands, my MacBook has booted up normally with no further issues.

Unfortunately, a simple shutdown and reboot did not solve my problem. For those still having this issue (Apple logo appears, progress bar at 0%), the following appears to have fixed the issue for me (for now):

Taking a cue from member hadamard, I removed any extraneous .kext files from the /Library/Extensions and /System/Library/Extensions directories, as well as the /Library/StartupItems folder.

I had upgraded El Capitan over Yosemite, whereafter I could not boot up normally. I booted into the Recovery Disk, made an emergency partition of my 1 TB hard drive (ensuring that it did not erase my other partitions), and did an emergency El Capitan install on that. From there I was able to make a Time Machine backup of my original boot drive (I ought to start backing up more!) before wiping my original boot drive, installing El Capitan again, and then migrating my settings, users, documents, etc. back after install. Unfortunately, when I rebooted after all this, I had the same problem– as it turns out, Apple migrates almost everything in the Migration Assistant. Comparing the .kext files from the aforementioned directories (between the emergency install and the migrated/upgraded install), I was able to determine which ones to remove (HINT: sort list by date, the oldest files are generally non-Apple and likely your problem).

My fresh install of El Capitan contained 266 kext files in the System Extensions folder, and 10 in the Library Extensions folder. Any more than that are probably third-party files. I had over 300 kext files, and though I am sure only 1 or 2 of them are the root cause, I removed them all to be safe (copied to a non-system folder in case I need to put them back later).

Hope this helps some people!

**** EDIT **** Double post. Read below. Sorry.

I didn't do the KEXT management and I was able to fix it a different way.

I solved mine by Flashing the PRAM (Command Option P R held during boot until it reboots.) Then I let it boot and it made it past the apple logo (it too a loooong time) and then I was able to log in (which also took a looooooooog time.)

Give that a try.

I forgot to add that I tried zapping the PRAM / NVRAM myself (I have a 2010 MacBook Pro). Didn't work, so I performed the steps outlined above. If some of you are able to fix the issue without removing the third-party .kext files, more power to you. Different fixes may imply different causes; hopefully one of the solutions here works for those who are still encountering this problem.

I also had the problem of old kexts and the Eltima Syncmate one was causing my screen to corrupt like a weird mosaic pattern at startup. After removing it in recovery mode I've had no further problems.