Q: Encountering STATUS_CODE_ERROR

Yes, I've encountered the same issue.  Looks like there are issues and you are not alone.  I discovered I could not login nor could I update apps this morning, March 11 at 6:45a EDT.  Hopefully the issue will be resolved soon

Same here... Even from 30,000 feet I am getting the same STATUS_CODE_ERROR as I am trying to purchase an app on my laptop. Well at least the support community is working so I know that something is broken at Apple ;-)

Just bought an older Macbook Pro and it's been locking up while using Safari. I thought the hardware was hacked somehow. I got the same Status_Code_Error while trying to download a previously purchased app from the Mac App Store.

same here it started this morning,

app store not working , every time try to buy an app it said : STATUS_CODE_ERROR 

unable to updates or download new apps....

I also am receiving this error. I just installed the Security Update 2015-002 just before I tried to update Xcode. Could it be related? It did update the keychain.

Does anybody know how to let Apple know we are all having this issue?  There does not appear to be support for the App Store application.

This issue also effects the App Store on iOS. Must be a system wide thing

Same problem here in Brazil.

It seems to be a problem with logging in App Store in the Mac (Yosemite 10.10.2).

When I tried the very same userid and password I was able to login in to use my iCloud account from the same computer and also from my iPhone.

Confirming same problem in Canada. Also, I did just update the security update first, for what that's worth.

Same problem here. Also I am connecting with a dev appleID (if that can help)

As per the Apple iCloud status page, they are having issues. Do not make changes at your end.

https://www.apple.com/support/systemstatus/