Error 14 on the iPhone occurs at the time your iPhone storage is at its maximum capacity. This means that the that your storage is already full and the device is not able to download or store any additional documents on the internal storage. This is when you'll be faced with the error 14 messages on your iPhone. The issue can cause your phone to become stuck on the Apple logo when updating, as large files in the device can slow down the performance of the iPhone or any other device gets slower when it happens. It can be extremely frustrating having a large amount of storage so try to always keep the process of deleting any unwanted files.