Hi Nicholas,
I have come across a similar issue, which says third party antivirus or third party are the cause for these errors.
If you are using any third-party antivirus software, you may disable it and check if the sync works.
You may refer to the antivirus manufacturer website to check for the options to disable antivirus.
**Note:**Even if you disable third party antivirus, Windows Defender will still be running in the computer. This will guard your computer from malware.
If the above does not help, perform clean boot.
Clean boot will help us identify if any third party applications or startup items are causing the issue.
To do this, follow steps from this link:
http://support.microsoft.com/kb/929135
Note: After checking the functionality in clean boot, follow the suggestions under “How to reset the computer to start normally after clean boot troubleshooting”.
Keep us posted on the status of the issue.