Fix: iTunes Could Not Connect to This iPhone an Unknown Error Occurred 

Whenever you get an error code, it usually always denotes what the problem is about. For example, sometimes iTunes shows the error message “iTunes could not connect to this iPhone. An unknown error occurred” with the code “0xE8000015” or similar. This code in particular, means that your computer is unable to recognize your iPhone. 

This can primarily happen when there are compatibility issues between the devices or their components or the lightning cable is not working properly. Other more possible causes are outdated iOS or iTunes, restrictions on your phone, lack of storage space, or a corrupted USB driver. 

To Solve This Error

Prior to following the solutions below, you may try simple fixes to resolve any compatibility issues. Check if you’ve selected the Trust This Computer option on your iPhone. Doing so will unlock your iPhone content on iTunes. 

Update iOS version and iTunes 

One of the simple and effective fixes to try is to update your iPhone and iTunes as well. This is because if there is a gap between the device versions, it can cause compatibility issues. You can update your iOS version in this way: 

1. Go to Settings > General. 
2. Tap on Software Update. 
   
3. Select Download and Install if there are any available updates. 

To update iTunes, follow these steps: 

1. Launch the iTunes app on your PC. 
2. Check the menu bar and click on Help. Then, select Check for Updates. 
   
3. Install any available updates. 

Disable Restrictions on iPhone 

Another way to fix this particular iTunes error is by turning off any restrictions on your iPhone. Especially settings like Content & Privacy Restrictions can keep the iPhone locked despite being connected to iTunes. 

1. Open Settings on your phone. 
2. Go to Screen Time and select Content & Privacy Restrictions. 
   
3. Disable the option. 
   

If you use iOS 11 or older, launch Settings > General. Tap on Restrictions and then select Disable Restrictions.

Reset iTunes Lockdown Folder 

iTunes has a dedicated folder named Lockdown which includes the app’s temp data. When you get the error code 0xE8000015, it’s very likely that the temp files within this Lockdown folder are corrupted. But, there’s a way you can reset this folder and get rid of the error. After you delete the folder, iTunes will create the directory again. 

1. Launch Finder and then select Go. 
2. Then, navigate to Folder. 
   
3. Type in “/var/db/ lockdown” and then press Return. Select View as Icons. 
4. Select all the files within the Lockdown folder and then delete them. 
5. Now, open iTunes and try connecting your iPhone again. 

If you’re on Windows, first make sure you’re using the administrator account. Then, you can follow these steps: 

1. Press Win + R keys to launch the Run dialog box. 
2. Type in %ProgramData% and then click on OK. 
   
3. Find and hit double-click on the Apple folder. 
4. Then, delete a folder named Lockdown from your PC. 
   

Manage iPhone Storage

Surprisingly, your iPhone storage also affects the performance of the iTunes app. So, if your storage is full, free up space by deleting photos or uninstalling apps. 

1. Open Settings and go to General. 
2. Tap on iPhone Storage. 
   
3. Here, you can check which items are taking up the most space on your phone. You can then delete accordingly. 

Put iPhone into Recovery Mode

If there are issues with your iPhone, you can troubleshoot it by putting it into Recovery mode. But, we recommend backing up your data first before using this method since it’ll get rid of all your data. Then, check if you’re using the latest version of Windows. Then, refer to these methods to start the Recovery mode.

1. Launch iTunes and connect your iPhone to your PC using a lightning cable. 
2. Then, follow these respective methods to set your iPhone to Recovery mode.
   
   For iPhone 8 or above: Hold and let go of the Volume Up button. Then, hold down and let go of the Volume Down button. Press and hold down the side button until you notice the Recovery Mode icon.
   
   For iPhone 7: Press and hold down the Volume Down button and the Power button together. Continue doing this until you see the Recovery Mode icon.
   
   For iPhone 6s or older: Hold down the Home button and the Side button together. Continue pressing the buttons until you see the Recovery Mode icon. 
   

Check USB to Lightning cable

Apple advises not to use any third-party tools, like a USB hub, or display and to directly use a USB to lightning cable. Additionally, check if the lightning cable you’re using is without defects. Check if there’s any hardware damage, like wires poking out or torn outer rubber sheath. 

A counterfeit Apple connector can also be why you’re having connectivity problems with iTunes. So, make sure your cable has a message written on it that says, “Designed by Apple in California Assembled in China/Vietnam/Indústria Brasileira.” It must also have the 12-digit serial number. 

Update or Reinstall USB Driver 

Finally, you can update or reinstall the USB Device Driver to resolve any connection problems with the USB device. First unplug your computer and then follow these steps:

1. Open Device Manager by searching for it in the search bar. 
2. From the list of devices, look for and select Universal Serial Bus Controllers. 
   
3. Find and right-click on Apple Mobile Device USB Driver. Then, select Update Driver. Here, you can either update the driver automatically or manually. 
4. Alternatively, you can also uninstall and then reinstall the driver. When you right-click on the USB Driver, click on Uninstall Driver. 
5. Now, restart your PC. Windows should find the best driver and install it on your PC automatically.