Errors while updating iphone 4
This usually fixes the issue as you no longer depend on Apple’s servers to download the firmware file.
This method is recommended for advanced users as it requires you to update to i OS 12.4 manually using i Tunes.
When a new i OS firmware is released to the public, millions of i OS users are trying to download and install it right away.
From the Control center Turn on for 10 seconds and Turn off again.Actually, this unwelcome error is not something new for i OS, and it is one of the most common issues when people download the new i OS software update.And on the earlier i OS update, people also got this error.In this many i OS users are reported Unable to install Update or Error occurred installing i OS.i Phone update stuck on progress bar & Unresponsive: the whole process of update i OS, first take backup your data & Settings in the separate root folder and then restore on new i OS automatically.So obviously it will take too much time, calm down and sit back, wait to complete the process.