iPhone owners risk losing all their files if they don't back up their device before upgrading to the next version of iOS.
Apple is introducing a new file system with iOS 10.3 called the Apple File System (APFS).
It will replace the Apple Hierarchical File System (HFS+) which has been used by Apple since 1998.
The new APFS is optimised for SSDs, boasts strong encryption, and improved file time stamping. It will be introduced across macOS, iOS, tvOS and watchOS.
During its implementation, APFS will automatically convert files on a user's iPhone to work with the new file system.
But given APFS and HFS+ are incompatible, should any issues occur during the switchover, user data could be permanently lost.
According to Business Insider, Apple will warn its users to back up their devices before upgrading to iOS 10.3.
iOS 10.3 is expected to be released towards the end of March. Developers have had the beta version of the operating system since last month.