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When you use Microsoft OneDrive for work or school (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:

Note: This article applies only to the previous OneDrive for work or schoolsync app (groove.exe). In most cases, we recommend that you use the newer OneDrive sync app (onedrive.exe) instead. Which OneDrive app?

  1. In the Microsoft Office Upload Center, you receive the following error message:

    Upload Failed
    Invalid characters

  2. In OneDrive. Sync problems appears in the notification area. When you click View sync problems, you receive the following message:

    X item can’t be synced with OneDrive.

    NOTE: X is the number of files that OneDrive is trying to sync.

    Under the Error column, the following message is also present:

    This file name contains invalid characters.

NOTE: This issue occurs if you're syncing files to Microsoft Microsoft 365 SharePoint Online or Microsoft SharePoint Server 2013.


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 Restrictions and limitations when you sync SharePoint libraries to your computer through OneDrive.

After you have deleted unsupported characters from the file name, the file will sync with OneDrive.

More information

This issue occurs because the characters that are listed in the "Solution" section are not supported by OneDrive.

For more information about OneDrive, go to What is OneDrive? 

Still need help? Go to Microsoft Community.

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