The initial demand for Apple’s (NASDAQ:AAPL) latest mobile operating system may have surpassed the Cupertino, California-based company’s expectations. According to a “reliable source” cited by Apple Insider, Apple has issued an internal, high-priority alert to its employees regarding server issues that are preventing some iPhone owners from activating their devices.

Apple made the iOS 7 update available to the public Wednesday. However, many users who have tried to download the latest iteration of Apple’s mobile operating system have found the update service is unavailable.

Although Apple Insider’s source claimed that Apple sent out a “P1” alert over the issue, it is not known how widespread the problem is or when the issue will be resolved. Despite multiple reports regarding iOS 7 download problems, Apple’s System Status Page was reporting no issues Thursday morning.

It should be noted that Apple has previously experienced server issues during releases for other versions of iOS. However, based on the high number of iOS 7 beta users, the latest version of Apple’s mobile operating system may be its most popular yet.

The redesign of Apple’s latest iOS was led by Human Interface Design Chief Jony Ive, who removed many of the skeuomorphic design elements that have long been a part of Apple’s mobile operating system. Although some users were initially put off by Apple’s radical iOS redesign, the apparently high number of early iOS 7 adopters suggests many iPhone owners are ready to embrace iOS 7.

Here’s how Apple traded over the past five sessions.

Follow Nathanael on Twitter @ArnoldEtan_WSCS

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