Q: El Capitan update won't boot

Glad you got it working. That is the recovery technique I recommended earlier.

Now that you have everything working, be sure to use Time Machine: Time Machine backs up your Mac - Apple Support. The converse of Murphy's Law states that merely having a backup generally precludes the need to ever require it.

I have this issue on 2 macs. My Macbook pro (2013) and iMac (2011). Both working after one or more setup sessions, but after shutdown or restart, the mac won't boot. One (Macbook pro) shows a blurry background image with the choice of user and then freezes with a bar that's empty below). Even the apple logo keeps burning on the cover when I close it. On the other (iMac) the same issue. I get a grey screen with the apple logo + a bar with no progress. I did a clean install afterwards with an external USB drive, but now the OS won't even install (it stops at 1 second 'till completion) and I've tried it 3 times today. I'm really dissapointed Apple releases a very poor OS full of errors. I have 5 macs (2 really old iMacs and 3 recent) and I've never encountered something like this. Today I've lost an entire day of work and it seems (as there is no solution for this problem) the rest of the week is also looking "excellent".
Fortunately my Mac Mini works fine. Only it has limited capacity so it's only for recreational use.
A very disappointed mac user.

Same for me. I have a late 2013 15" mbp woith Yosemite on it, max memory, max ssd, 2 gpu's and now on the second install of el capitan it hangs at the immediate startup page with an empty progress bar. First time it allowed me to enter my password and then hung. Now it doesnt even get that far!

This is what Apple calls a final release for the public?

For all his faults, I don't recall these kinds of issues when Mr Jobs was alive and in command!

Rossmon

Fortunately, I made a time machine backup, always do.

And now mine has done the same thing after running most of the day and booting up and shutting down a couple of times to try to solve another problem....

Well done Apple, you've really f**ked this one up haven't you.

I'm going to have a go with the CMD+R and see how that pans out, but given what I've read around here today I'm feeling less than optimistic that my 7 month old macbook pro will be anything but a large coaster!

Argh!

I have a fix.

Problem.

After downloading and installing El Cap on MacBook Air 13 inch early 2015 there are two requests for login. The first request has a fuzzy image of Yosemite valley in the background. Then you are requested to login again. This second login is on a grey screen. The progress bar stops without completion.

No change for 8 hours.

we are going to clear some files that are stopping the installation from loading.

Solution

Shut down.

Restart holding down CMD R.  Release Keys when you see the apple logo.

Login when requested.

Desktop should load. If it does not, shut down and repeat.

When desktop loads, GO/LIBRARY and drag folders; CACHES, STARTUP ASSISTANTS, STARTUP DAEMONS to trash

(Hold down the option key to reveal the LIBRARY)

MACINTOSH HD/LIBRARY and drag folders; CACHES, STARTUP ASSISTANTS, STARTUP DAEMON and COOKIES to trash.

Shutdown.

Restart holding down CMD OPTION P R. Continue holding down the  CMD OPTION P R keys until you hear a second 'bong'. Release keys

Login when requested.

Your desktop should now load.

Empty trash.

Loads of people reporting exactly the same problem. I've had it too and am having to restore from time machine back to Yosemite (mine is late 2010 21" iMac)

it's really disappointing. I actually had the same issue with Yosemite when it came out...I restored from back up, waited a few weeks then tried it and it was fine suggesting Apple are not doing their due diligence before releasing.

Poor

I have a fix.

Problem.

After downloading and installing El Cap on MacBook Air 13 inch early 2015 there are two requests for login. The first request has a fuzzy image of Yosemite valley in the background. Then you are requested to login again. This second login is on a grey screen. The progress bar stops without completion.

No change for 8 hours.

we are going to clear some files that are stopping the installation from loading.

Solution

Shut down.

Restart holding down SHIFT key.  Release Keys when you see the apple logo.

Login when requested.

Desktop should load. If it does not, shut down and repeat.

When desktop loads, GO/LIBRARY and drag folders; CACHES, STARTUP ASSISTANTS, STARTUP DAEMONS to trash

(Hold down the option key to reveal the LIBRARY)

MACINTOSH HD/LIBRARY and drag folders; CACHES, STARTUP ASSISTANTS, STARTUP DAEMON and COOKIES to trash.

Shutdown.

Restart holding down CMD OPTION P R. Continue holding down the  CMD OPTION P R keys until you hear a second 'bong'. Release keys

Login when requested.

Your desktop should now load.

Empty trash.

Hey

Thanks for posting this, I have lost the will to live with Apple today and appear to be one of the lucky ones were a restore back to Yosemite via Time-Machine has worked.  Hopefully your solution fixed the problem for you and others, but I'm not game to try another apple update until those idiots sort their complete mess out.

Same problem here on a mid-2015 MacBook Pro 15" - I was able to login once, and then hangs up after a reboot - get to enter login name and password and then hangs with an empty bar.

I tried Internet Recovery but after 3 hours of downloading Yosemite, it told me that it couldn't install because a later version of the OS was already installed. Would have been great for it to check first.

I had to restore to a TimeMachine backup, which restored Yosemite too.

No upgrade to El Capitan now for me until this is fixed. Sadly I did have time to upgrade the Notes app when 10.11 ran the one and only time, (and on my iPhone on iOS 9), so Notes is no longer capable of synchronising across my devices.

Hi folks.

Same issue here. Mac book air 11". i downloaded El Capitan from AppleStore. All was good. When my mac reloaded it stucks at 100% with black loading bar. I tried different work-around to fix it.

- startup in recovery mode,

1.- using disk utility. My HDD is ok, no error found.

2.- to re-install El Capitan again. i did it twice. it didn't work. same issue when mac finished installation.

- startup doing a NVRAM reset --> by holding Alt+CMD+R+P while holding the power button. When you hear the POST (Power On Self Test), or boot chime, keep holding all the buttons until you hear the second chime and then let go.  No luck

- startup on single-user mode. i run fsck and mount trying to discover some issues inside my HDD...all was ok. Just in case i followed this user-guide from 5th comment André Ferraz. http://appletoolbox.com/2014/09/mac-fix-white-screen/   --> urquhartps it appeared your message --> "Waiting for DSMOS"

- startup in verbose mode ... my system hangs in this message for hours "Waiting for DSMOS"

Very angry, i am not able to work with my computer at all. Really Apple, this is crazy. I'll try urquhartps's solution...make a backup of my HDD and try to make an upgrade from the scratch...but really, this crazy Apple...

Hey everyone!

One more MacbookPro 15 retina 2014 with this stuck At first I was updating via App Store,  stuck on 90% progress bar... After clean install and restoring from time-machine, restarted. Now it freezes on 100% progress bar. Will try to reinstall now and won't shut down it.  Apple forgot their ''It just works"

I have the same problem.... won't boot

apple logo and bar empty ... what helps temporary...reload 10.11

install , let him boot and dont shout down by power button !!

leve the mac in standby... this works as long, as i keep my macBook  in this condition an not try to reboot !!!!

reg

juergen

Hi,

mine is a late 2013 Macbook Pro 13" Retina running Yosemite 10.10.4.

I tried a update to El Capitan twice with no luck.

First time it stuck at about 90% at the black screen with Apple Logo. I forced a shutdown and restarted. I was prompted with my local users, clicked one, entered password and the progress bar got stuck at 100%. No login. I restored from time machine - 9 days old, bad enough, but still ok.

Second try almost same picture with the difference, that after a forced reboot, I was not presented the login screen but all times the same black screen with Apple Logo and a 90% progress bar.

My HDD is encrypted with FileVault - maybe that's a hint ?

Cheers

Christian