Dear John,

Thanks for contacting us and i am truly sorry for the delay reply due to National Holidays. It will be appreciated for your generous forgiveness.

These are some of the common reasons behind this error 54 iTunes.

An outdated iTunes can create this annoying issue.

A corrupted iTunes file or improper installation is another reason for iTunes Sync error 54.

Virus attack or web threat is responsible for this irritating issue.

The problems with the PDF files becomes a barrier in the file sync process.

There are some of the simple steps you can use to remove this kind of error effectively. Moreover, it enhances your device’s performance.

1. Upgrade iTunes;

2. Remove Malware;

3. Upgrade iOS;

4. Edit Windows Registry;

5. Remove and Re-import iTunes Content;

6. Give Full Access Permission;

7. Delete PDF Files from iPhone.

To get detailed instructions, please just refer to the post below:

https://itunessupport.org/blog/fix-error-54-itunes/

I truly hope this post would be helpful for you.

If there is anything i can help you with, please just let me know.

Enjoy a nice day!

Best regards,

Niki