Q: Mac OS X 10.8. Login to iCloud via System Preferences invokes "You can't sign in at this time. Try signing it again."

that didnt work! This is really starting to get on my nerves, one of the big reason i paid 20 dollars to get ML was because of all the good reviews about icloud, and now it doesnt work ? ive been trying differenent things for about 2 days now

i really need a solution for this!

Reset key chain DID NOT, work for me, and I renamed the backup it made back to the original. (Note to others: I may have had permissions or other issues due to the way I upgraded to Mountain Lion by creating a new user and moving things over manually.)

HERE IS HOW I FIXED IT: (I don't know what the ramifications are, so this will make you a backup too.)

I threw away my Library > Application Support > iCloud folder.

1. In the Finder, choose Go, hold down the option key (alt) and choose Library which will appear in the menu.
   
2. Navigate to Library > Application Support and option-drag the iCloud folder to your desktop (that will make a copy).
3. Now drag the iCloud folder that is in Library > Application Support to the trash, enter your administrators password when prompted.

Then try entering your info in the Preference Panel again.

I did this and found that there is no icloud folder in application support.  That is my problem i guess

All attempts to find any iCloud folder within G0 --> Library--> Applicaton Support  have failed.  It is not there.  A folder with that title is not found anywhere else, either.

In order to activate PhotoStream FROM my Mac (to enable ability to share photos to other devices from the Mac) I need to login through Systems Prefs....  my other devices are sharing photos as long as they originate on an iPad or iPhone but photos will not stream from the Mac to these devices.  

Please advise!

GB

The folder is NOT in the "root" directory "Library" but under Users>Your Username>Library>Application Support>iCloud

Worked for me!

Have done this .... there is no iCloud folder there.  Have seen another thread with same problem. 

Why is there no iCloud folder in Application Support for some of us???

Just spent 20mins on phone with Apple Support. Turned out I had a file called iCloud of zero bytes in the '{Username}>Library>Application Support' that wasn't a folder. Deleting this solved login issues. good luck

i found the fis

1.go into system pref/users and groops and creat a new admin user and then you are going to remove the user that is haveing the issue signing into icloud and have the new user you created be the user you just deleted you are going to want to save the home folder of the user you deleted so that way you dont loose you documents

Thank you. This fixed it for me. There wasn't an iCloud folder in my Application Support folder. Instead there was a iCloud document that was 0 bytes big. I just moved it to my desktop and iCloud works fine!

To all the folks who can't find the iCloud folder in the Application Support folder. Make sure you are looking in your user account and not from the hard drive. It is normally hidden.

To do this:

1.) Go to the Finder.

2.) Click on "Go" in the Finder Menu.

3.) Press and hold the "option" key. "Library" should appear. Select that option.

4.) A finder window will appear with a greyed out (but selected). That's where you will see the "Application Support" folder that will have your "iCloud" folder.

5.) Open the "Accounts" folder and delete all the files in there.

Thanks Mike, Your advice helped. I have tried so many other advices, but to go to "Library" (that I did not know existed, and in the "Application folder" finding an empty "ICloud" folder that I moved to desktop was all that was needed to have my Mac accepting my ICloud identity!

This worked for me.

Thank's!