El Capitan - App store and iTunes won't let me sign in

I have the same problem on my macbook pro 13 " . I can not update any applications. Additionally my battery consumption is reduced by 50 %

A Safe Mode boot deletes system caches that may help after an OS X update or upgrade.

Top left corner of your screen click the Apple  > Shut Down.

After your Mac shuts down, wait 10 seconds, then press the power button.

Immediately after you hear the startup tone, hold down the Shift key. You should press the Shift key as soon as possible after you hear the startup tone, but not before.

Release the Shift key when you see the gray Apple logo and progress indicator.

Once you are in Safe Mode, go back to the Apple  menu. From the drop down menu click: Restart

About Safe Mode

It is correct. We must solve the issue of access to updates for the APP , so when they get new updates solving the bug that causes consume battery.

I am having this same issue. I cannot log in to any of apple's products from my Mac, but I can login to icloud.com or apple's commenting system, so the issue isn't with the account.

I'm not connected to a VPN (Seems like this can cause this issue in others), I have gone into safe mode and the issue still persists. I've tried creating a new admin account, signing out of all the apps (which is why I'm no longer signed in to the store...), etc.

I'm not exactly sure what is going on, and it doesn't seem to be a super wide-spread issue otherwise it would be easier to find comments online.

I'm running the 2013 15" macbook pro retina. I have only had this issue since updating to El Capitan.

Any assistance would be greatly appreciated!

Thanks!

See Since upgrading to El Capitan I keep getting the same error message 'Error connecting to Apple ID Servers' so I cannot log into my iTunes or iCloud, yet all ok on my iPad

I know this does not help anyone, but if someone finds an answer, at least I will be notified...I think.

I have a Mac Mini i7 processor....the install failed several times (That should have been my first hint) I booted from another system and was able to download El Cap... I installed, and everything works fine, just cannot log into iTunes. So I cannot watch movies I have purchased without verifying my Apple ID. I try and all I get is the log in window and a spinning wheel. Good news is that I can re-boot into another system (10.9) and everything works fine. I guess I will have to stay booted into this drive until Apple fixes this problem.

AGAIN...any answers, PLEASE post them here!

Thanks!

I have this same issue too.

My Mac Pro went in for a logic board replacement a couple of years ago and the engineer forgot to flash my computer's serial number so in About This Mac my serial number reads as 'Unavailable'. I've never been able to sign into Messages on previous versions of OS X which I understand is due to the missing Serial No. I wonder if Apple has changed how it checks for a real Mac and my real Mac Pro looks like a Hackintosh?

Can those of you, like me, who are locked out of iTunes and Mac App store check if your serial number is showing in the About This Mac area please?

I've created new Admin accounts and run in safe mode and still no joy. The login spinner just spins until I have to force quite either iTunes or the Mac App store.

Can anyone think of anything else to try other than reinstalling Yosemite?