Software Update Failed Error for iOS 15.7 on iPhone 8

Thank you DeadRedPanda! After getting free space above 6GB, update 15.7 successfully downloaded and installed. I do find this an odd requirement, though, considering the update was only 326MB. And it would be helpful if Apple would add this requirement to the error message.

It finally worked for me. iOS 15.7 downloaded fine and installed successfully on my iPhone X.

The trick is to clear more space and ensure that you’ve at least 10 to 12 GB of free space. This is weird because the download is under 335 MB. But, once I cleared more space and brought it to about 11 GB, everything worked magically!!

Ok.. finally made it, not without a struggle or some moments of risk..

I had to clean data and have 12-14GB free

phone got stuck on verifying update , had to power cycle it and than it did and finished update, not without fear, it made break the phone

It is the storage capacity on your phone, I'm convinced. I earlier posted that but backed off of it because several people said that they had "plenty of storage". My iPhoneX had 3.2 gigs of space and repeatedly failed, despite the update being only a small fraction of that. However, I cleared a lot of photos/videos and increased the space to 19.4 gigs and 15.7 updated easily. The update must have to store a lot of the iOS while it is updating is my guess. Another person of this forum had similar experience by increasing his space drastically. BTW, I use Simple Transfer Pro App to transfer photos. Yes, the Pro version has a one-time cost, but works so superbly and allows unlimited numbers of photos and videos to be transferred. Free version only allows 50 at a time.

Same problem, same message trying on an iphone 12 mini. Tried with and without wifi/cellular. Have room for update. Turned phone off and on. Turned on and off VPN. I have fios 500mbs symetrical. Still Software Update Failed An error occurred downloading iOS 15.7.

Try to free up storage, that helped to some of us.

In rare cases, having at least 6 Gb of free space is enough to install the update, but I had to clean up 12 Gb to proceed with the update on my SE 2nd gen.

Hi everyone. I appreciate all the comments and suggestions to my post earlier last week. Amazing Apple never responded to our complaints and issues. Once I freed up space on my phone the software downloaded and installed.

Again tried updating to 15.7 (~300 MB update file, on iPhone SE 2nd ed with > 10 GB spare), still failed for no stated reason. Gave up and upgraded to 16 instead, worked straight away with a > 2 GB update file. Go figure.

Apple, you put your B team on 15.7. It shows. Please fix that.

This is a user-to-user forum, not a way to communicate with Apple. And millions of phones have updated to iOS 15.7 without problems, so there is nothing that Apple can do globally; the problem is with your phone or environment.

OK, so I had a lot of the same problems with my IPhone 8. Was only at 2Gb capacity, increased it to 5-6GB, dumping photos to PC storage. Then it still sat at “Preparing Update” and i just sat there keeping it from going to sleep and the little blue bar ever-so-slowly went up and completed after 15 agonizing minutes as i read this blog. But it finally did it and it is now updating with white little apple and white bar. Slowly. So. Dang. Slowly.

True dat, but seemed much longer than other updates in the past. But it only worked for me if i babysat it. I know it’s not conclusive, could be other factors (it was morning rather than evening, some apple engineer finally said “OK, enough already, I’ll let ‘m have it.’)

I had this problem. I had originally initiated install and next morning did not see any error except that the update was still showing in settings. I was able to install 16 and 15.7 doesnt show any longer. Hopefully it corrected with the 16 install.

I’ve got the same problem. I have enough space. Tried to download and install on PC via itunes. It says it’s going to take 38 hours to download. Ridiculous! Shouldn’t be when it’s only three hundred some mb. What gives apple? No solution anywhere to be found.

Using a PC it does a complete reinstallation. The download to iTunes is about 3.5GB. Updating over the air just downloads a patch for “dot” version upgrades. And the download time is controlled by your internet connection speed and nothing else.

What was the result when you followed the guidance in the Related Article at the top this page? If the Related Article doesn't answer your question please post back with more details about the issue and another user in this user-to-user forum will try to help.