Now it's totally fuched. I rebooted, and now the screen is black, with white letters showing the names of the folders on the desktop - no icons. I can navigate by moving the cursor to where I know the Apple and Finder are. Preferences don't work. I tried a soft reboot and the progress line made about 50% progress in 35 minutes. I had to leave and won't be back until Monday. I was so ticked off I turned the monitor off and walked out. Am I going to find a smoking heap when I get back to town?
To all who say they like Apple because, "It just works" - that isn't universally true.

Tried to use the printer hooked up to the desktop computer, and the laptop can't seem to connect to it, even though it is the printer selected. I think I might go back to snow Leopard, as everything worked on it.

Reboot in rescue mode.

There is a hidden partition which will allow you to reinstall the OS.

How old is the hard drive? May have been failing.

Thanks. I'll give it a shot when I get back Monday.

Time machine works flawlessly on mine - possible configuration issue (?)

Sounds like more than a configuration issue . . .

I have had any issues until yesterday: I couldn't type in MS Word on my MacBook.

Lots of people having issues: https://discussions.apple.com/thread/6602322

Opening and closing seems to work for now.

I have Office 08 and Yosemite- no issues.

rjp

Just recovered my Air and thought I would share in case it helps someone else.
Backstory I had a USB to serial converter connected and finished my work so just unplugged it; I got a weird crash screen I have never seen before. I rebooted and everything including login took forever 0 spinning beach ball.

I hooked up a USB drive and rebooted again (key point) if you have wireless or an internet connection when you boot do and Apple (Command key) R holding down an fit will boot to recovery. I installed Maverick on the USB drive and rebooted from it.
I ran all the disk utilities and it said there we no issues on the Air's SSD drive. I rebooted one more time and still beach ball.

Rebooted again and Command R until I got the recovery screen and re-installed the OS. Booted and it's all good now (typing on it)

I do backup always so I wasn't worried it's just a pain when they crash.

I hope it helps someone else.

So despite owning the hardware Apple's OSX is prone to crashing on a proprietary based 'upgrade'? Does not promote much confidence in the "it just works" mantra. We have 1 MB Pro and 2 iPhones in the house. I am terrified to update their OS version. Until they quit working I will hold where they are thanks. Welcome to Windows ME.

Sh-t happens. Memory gets corrupted, drive bits too. Doesn't need to have anything to do with upgrading to Yosemite. I suspect the OP has a hardware problem, failing drive, etc.

I tend to stay one step behind the leading edge OS and haven't had a problem in years. I regretted the only OS upgrade I've done on an iPhone. It wasn't a problem, just not an improvement. No way I would condemn myself to a life with Windows just because I have a Apple OS problem every 10 years or so.

Ordering a new iMac this morning.
I did a rescue start up on my old Mac and got enough of a screen to start a restore from backup. It's running now on Mavericks, but the hard drive cycles constantly and about every 30 seconds to a minute all the images on the screen go away, then come back. This computer went into service in 2009. It's toast.

For grins.... I just got a mini and a 4K monitor so I now have a Retina screen (albeit at a lowly 1920 res). Did you know the folders icon in Yosemite (and possibly earlier OSes) is actually 3 folders stuck together and staggered ???

I could never see that before.. Yes it's trivial and stupid, but I've used a mac since 1984 and I just noticed that last week ;-) Retina is really nice !!!

http://forums.pelicanparts.com/uploa...1421097637.jpg

Migrating data to the new computer now. When I restored from backup on the old computer this morning it calculated that it would take 2:45 minutes. It took about an hour 50 min. Using the same backup drive, the new computer calculated 35 minutes to migrate all 700 meg. It will be interesting to see if it is really that much faster.

I'm going to have to get sunglasses to use this 27" Retina display. Holy Moly is it big and sharp.

So, just to be clear...

Apple royally screwed up your computer, so you went out and dropped some major coin on another Apple?

AFAIK there are only two ways for software to bork hardware.

Code that intentionally causes CPU loads to spike for an extended period of time causing excess heat that affects soldered connections. But you'd notice the fans screaming like crazy unless other code was introduced that disabled them.

Code that causes the hard drive to thrash or read/write excessively causing premature failure but I doubt you could make that happen in one days time and again the user would likely notice the sluggish behavior.

Yes, when I looked at my computer and the number hours I had on it I decided a new machine was in order. The computer went into service in 2009, one of the hard drives is from a computer I had in 2004. The theory is the computer was on its last legs and the extra load put on it by Yosemite pushed it over the edge.
If this had been a newish computer I would had to consider an alternative to Apple.

Got my new iMac with retina display a couple of weeks ago, I hate it, Cant get anything to work, tried tranferring documets to the new machine, folder is locked and Apple instructions won't unlock it, thing asks for password any time you blink, cant send email account is offline, cant find anything that works to bring it online, lots of others on the web with the same issues. I loved my old leopard . I think Apple has lost site of what attracted me to them in the first place. I intend to ask to send this POS back.

You have a permissions or account problem.

When you set the new machine up did you use the migration assistant?