San Francisco/Sydney, September 18

A significant number of Apple customers are reporting their mobile devices have crashed after attempting to upload new iOS 9 operating system, latest in a line of launch glitches for the tech giant.

Twitter and other social media were awash with disgruntled customers reporting two distinct faults, with one appearing to be linked specifically to older models of Apple iPhones and iPads.

“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 today. “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.”

Another iPhone user, Zorry Coates, said she had spent three hours in the Apple store and had been left with the option of either returning her phone to factory settings — losing any non-backed-up data — or waiting until Apple technicians announced an update.

“They said they were aware of the problem and their engineers were working on it 24/7, but they couldn’t tell me when — or how — I would get a solution,” Zorry said. “I’m very annoyed because it’s wasted half my day. They pride themselves on being flawless.”

Apple’s headquarters in San Francisco did not respond to a request for comment. An Apple spokesman in Sydney said the company had no comment.

Despite any troubles, significant numbers of iOS users had upgraded; more than 16 per cent, as per Mixpanel, a San Francisco, California-based analytics company, as of 4:00pm on Thursday.

Charlie Brown, a technology expert at Sydney-based Cybershack, said any number of dissatisfied customers was significant in the social media era, particularly following troubled rollout of iOS8. Apple released several further updates to iOS8, but some bugs were never fully fixed. “The risk to Apple in terms of having dissatisfied customers is that as their customer base grows, so will the number of those dissatisfied customers.”

One group of users reported that iOS 9 upgrade would fail after several minutes, requiring them to start the process over.