Solved: How do I fix “sync session failed to start” iPhone/iPad to iTunes?

Problem: iPhone and iPad reported issue when trying to sync iPhone/iPad with iTunes, the error “sync session failed to start” prompted. The detail error message as below:

The iPhone “iPhone” could not be synced because the sync session failed to start.

Follow below solution steps to resolve the sync session failed to start issue.

Content Summary

Potential Causes
Solution 1: Force close all running applications
Solution 2: Restart iTunes and reconnect iPhone/iPad
Solution 3: Soft Reset
Solution 4: Update iOS to the latest build
Solution 5: Update iTunes
Solution 6: Delete the previous backup
Reference

Potential Causes

• Running applications stop the sync process
• Missin iTunes opponents
• Outdated iTunes and component software
• Corrupted iTunes software or iTunes library
• Faulty or incomplete iTunes installation and iTunes related component installation.

Solution 1: Force close all running applications

On your iPhone, force closes all the running apps in the multitask window.
For iOS 7
Step 1: Click the Home button twice.

Step 2: Tap and hold on the app.

Step 3: When it starts to jiggle, tap the X to close it.

Step 4: Repeat until all the apps have been closed.

For iOS 8
Step 1: Click the Home button twice.

Step 2: Swipe the application preview window upwards to close the app. You can close multiple apps at once.

Step 3: Repeat until all the apps have been closed.

Solution 2: Restart iTunes and reconnect iPhone

Step 1: Exit iTunes.

Step 2: Connect iPhone to PC using the USB cable.

Step 3: Start iTunes.

Step 4: If iTunes starts automatically, close it and restart it with the iPhone plugged into the USB port.

Solution 3: Soft Reset

Step 1: Hold both Home and Sleep button for around 10secs until you see the Apple logo then release.

Step 2: Returns to Home screen.

Step 3: Connect to sync.

Solution 4: Update iOS to the latest build

Step 1: Exit iTunes and disconnect the cable from PC.

Step 2: Put the iPhone on charging and connect it to a Wi-Fi network.

Step 3: Open Settings and tap on the Apple ID.

Step 4: Tap on iCloud > iCloud Backup > Backup Now button and wait for the backup process to complete.

Step 5: Open Settings > General > Software Update. If the iOS update is available, then download and install it.

Solution 5: Update iTunes

If the iTunes is downloaded from the Microsoft Store, go to Microsoft Store and click Downloads and updates to check when it was updated last time.

If the iTunes is downloaded from Apple’s website, open iTunes > Help > Check for Updates.

Solution 6: Delete the previous backup

Step 1: Open iTunes.

Step 2: Click on Edit > Preferences.

Step 3: Choose the correct device.

Step 4: Delete the previous, if the Reset Sync History button is enabled click on it.

Reference

Apple Communities > Sync session failed to start