Apple App Store STATUS_CODE_ERROR
Many users report problem downloading / buying applications on Apple App Store today or Max App Store.
Appstore usually reports various errors like "STATUS_CODE_ERROR".
Reports indicated also difficulties with iOS App store and iBooks Store for few hours today.
Apple reports that App Store and iTunes store is unavailable for all users:
It looks like that the problem with iCloud Mail and iCloud Account & Sign in is solved 4 hours ago.
UPDATE: All problems are solved, Apple has updated services status page with message that "There are no reported issues at this time."