Fixed: iTunes Backup Couldn't Be Completed Error

1. Do As Follows:

1). Check your iTunes version. Update iTunes to the latest version if it's not. This solves most of iTunes not working problems.

2). Connect your iPhone to computer via USB cable and select your iPhone in iTunes. If, unfortunately, your iPhone doesn't show up in iTunes, check the troubleshooting tips before you go further.

3). Shut down both your iPhone and computer. After a while, re-start them.

4). Do the iPhone file backup on other Mac/Windows computer if you have more than one computer.

5). Use iCloud to backup iPhone file data. If iPhone won't backup to iCloud, click here to get the solutions.

6). Contact Apple Support.

7). Try best iTunes alternative - MacX MediaTrans to smoothly backup iPhone photos, music songs, videos, iBooks, iTunes purchases to Mac, as well as transfer any files (non-Apple MKV, AVI, FLV, VOB, WMV, WMA, FLAC, etc.) from macOS to iPhone without using the troublesome iTunes. And it can also delete and manage iPhone songs/videos/pictures, create iPhone ringtones, convert M4P to MP3/M4V to MP4, encrypt videos/pictures to safeguard your privacy, mount iPhone as USB drive and more.

2. If iTunes Backup Failed Because An Error Occurred

Sometimes, you would receive the message, saying "iTunes could not backup iPhone because an error occurred". That might be caused by varied types of reasons. You can try the normal approaches to take a chance, including update iTunes, re-launch your computer, delete iTunes backup, change another disc to save iTunes library media, etc. If all of these don't work for you, check this guide with full fixes to iTunes backup error.

3. If You're Told That Your Backup is Corrupt or Incompatible

In case you can't restore iPhone from an iTunes backup because your backup is corrupt or incompatible, two methods are worthy of your consideration.

Solution 1: Delete iTunes Corrupt or Incompatible Files and Backup Again

Step 1: Head to iTunes and tap "Edit" from the top menu.
Step 2: Choose "Preferences" from the dro-down list and then pick up choose "Devices" (as the picture shows below).
Step 3: Opt for your iPhone [xxx] under "Device backups" > press "Delete Backup" option > click "OK" and iTunes will begin to delete the last iPhone corrupt or incompatible backup. Afterwards, you're supposed to create a new iPhone backup.

Also See How to Fix iTunes Backup iPhone Because of Disconnection Error >>

Solution 2: Resort to Top iTunes Alternative

It's known to all that iTunes only supports you to sync and backup files with Apple ecosystem formats, such as the video audio formats MP4, MOV, M4V, H264, HEVC, MP3 and picture formats .jpg, .png and .heic. However, things become much better when it comes to best alternative to iTunes - MacX MediaTrans, which gives you the maximum freedom to flexibly transfer and sync files between iPhone and macOS. Unlike iTunes the "all backup" style, this iPhone manager allows you to bulk or selectively backup iPhone photos, music, ringtones, videos, TV shows, iBooks, podcast, iTunes purchases, etc. to macOS. Thus, you can directly delete or skip the corrupt files and continue the normal files backup. Time is saved and the probability of backup failure is badly declined to almost zero.

That's not the whole story. What sets this iPhone backup software apart from other competitors is that it provides you with 2-way sync, letting you also transfer anything from macOS to iPhone without compatibility issue, cuz it has built-in conversion feature to auto compress and convert non-Apple video/audio formats to iPhone friendly formats with optimum file size. No iTunes involvement!

How to transfer files from macOS to iPhone without file corrupt or incompatible problem? Read below:

Step 1: Launch iTunes and click "iTunes"> "Preferences…". Tap "Devices" and tick the option " Prevent iPods, iPhones, and iPads from syncing automatically." This step is to prevent any data loss.

Step 2: Connect your iPhone to Mac via USB cable and launch this iTunes replacement for macOS. The latest iPhone is supported.

Step 3: Click "Music Manager" on the home screen > select "Add Music" > choose mp3, hot singles, playlists, ringtone from local computer > hit "Open" button. Then the selected songs will be imported to your iPhone instantly.

Step 4: Give the final hit to the blue "Sync" button on the Window. Then the imported music and audio files will be instantly synced to your iPhone without any corrupt or incompatible iTunes errors, cuz it can auto skip the damaged files and convert the non-Apple formats to iPhone supported formats. Just several seconds or minutes later, you can check if the files are all appearing on your iPhone.