Yosemite-great but login hangup is a problem

I am in Mac/Apple support at my place of work. Love Yosemite features but the login hanging up is a problem. I have run across it at least ten times. Most of our accounts are encrypted and it seems to effect those accounts easier. Any suggestions?

What is "the login hanging up" you referred to? I've never seen it.

When you boot up in Yosemite, the line that is filling in while it is booting up, hangs at about 40% and doesn't get any further. Doesn't allow you to boot up.

Patience, Grasshopper, the line will suddenly jump from the 40% to nearly finished. I don't know what OS X is doing there (I think it's fsck-ing, but not sure if that's ALL it's doing.) I've never seen it hang up and refuse to finish.

Wow! I have waited a good half hour and no movement for a few of our Mac users here.

Wow, that is not, AFAIK, definitely NOT normal. I've not seen it here, but I'm not logging into a network, just my local machine. I do know that the line is new in Yosemite, but I've read somewhere that nothing new is happening, it's just Apple giving folks an indicator that things ARE happening. Might be worth a call to Apple. Even if you don't have AppleCare, you can still get Yosemite support.

I'll take a guess and FileVault is enabled on those Macs, and running Yosemite.

If so, have a read on this article that just may help:
FileVault bug makes Yosemite pause or hang at login | MacIssues

Nice find. FileVault does it again! I can understand the need for encryption and protection of sensitive data, but when it locks you out, that kind of defeats the purpose of using it in the first place.