While the new operating system of Apple is being praised, it is also being criticized by those annoyed iPhone users whose devices crashed and were not able to upload it.  Tech analysts blame it to overloading due to the simultaneous uploading of Apple fans who cannot wait to try the promising features of iOS 9. 

The much-awaited release of Apple iOS 9 happened on Wednesday, Sept. 16.  A lot of iPhone users are so excited to upload the OS but gets frustrated in the end.

A large number of Apple customers reported that their mobile devices went crashing after trying to upload the operating system which is the latest in a line of launch glitches for the tech giant company.  Aside from Twitter, other social media are flooded with angry customers regarding two notable faults with one that seems to be linked particularly to older models of Apple iPhones and iPads, reported Reuters.

"It is beyond inconvenient to not be able to use your phone for a day," said student Pip Cordi as staff in the Apple store in central Sydney looked at her phone on Friday. "I have a lot of apps that I use for school - things like language apps and dictionaries and that's all really important for my studies."

Apple's San Francisco headquarters did not reply to a request for comments late Thursday.  A Sydney Apple spokesperson said the company had no comment.  However, more than 16% of the iOS users were successful to upload the operating system despite any troubles as of 4 p.m. PDT (2300 GMT) Thursday, according to Mixpanel, an analytics company based in San Francisco, California.

The problem might be caused by servers that get overloaded when a large number of users tried to download all at the same time, said the tech analysts.

Despite the issues, a lot of iPhone users are still patient and waiting to get the iOS 9 uploaded.  The embarrassing failure would not stop iOS 9 to shape up and be a great success priding itself with these highlights making it interesting: improved battery life, low power mode, reduced installation size, 'Proactive' addition, Smarter Siri, improved multi-tasking, upgraded Apple Maps, 'News' addition, 'QuickType' addition, and improved Notes, Forbes reported.

iOS 9 can be uploaded with eligible devices such iPhone 4S and later, iPad 2 and later, iPad mini and later, and iPod touch 5th generation and later.  Since iOS is notably smaller than previous iOS releases, space is still needed to download the update and a 50% minimum battery capacity before it can be installed.