Article ID: 2813150 - View products that this article applies to.
When you use Microsoft OneDrive for Business (formerly Microsoft SkyDrive Pro) to sync files from Windows Explorer to a Microsoft SharePoint site, some files may not sync as expected. Instead, a red X is displayed on the file icon in Windows Explorer and then you experience one of the following problems:
To resolve this issue, delete any invalid characters from the file name of the Windows Explorer file that you're trying to upload to the SharePoint site.
For more information about the characters that can cause this specific issue, see the “Invalid characters” section in the following Microsoft Knowledge Base article:
2933738After you have deleted unsupported characters from the file name, the file will sync with OneDrive for Business.
(http://support.microsoft.com/kb/2933738/ )Restrictions and limitations when you sync SharePoint libraries to your computer through OneDrive for Business
This issue occurs because the characters that are listed in the "Solution" section are not supported by OneDrive for Business.
For more information about OneDrive for Business, go to the following Microsoft website:
What is OneDrive for Business?
Still need help? Go to the Office 365 Community