Fixing OneDrive (macOS) sync issues caused by invalid file names


The following characters aren't allowed in file and folder names for OneDrive for work or school on Microsoft 365, and SharePoint in Microsoft 365:

" * : < > ? / \ |

If you attempt to upload files or folders to OneDrive with names containing these characters, you may notice that OneDrive is unable to finish synchronizing your data to the cloud. This article explains one way to fix this problem on school-issued macOS endpoints, and is particularly useful if you have a large number of sync errors to fix.

Before You Start

  • This article assumes that you have already signed in to Microsoft OneDrive (macOS) and are using it to store or access data

  • If you click the OneDrive app icon at the top of your desktop (

    near your wireless icon), OneDrive will report any sync errors with the OneDrive needs your attention message, as shown below:

  • If you have a small enough number of sync errors caused by invalid file or folder names, these can be fixed manually by following Microsoft's documentation

  • If you have a large number of sync errors, please follow the steps below to attempt to fix the errors with a CIT-provided solution


  1. Open the CIT Self Service application from your Applications folder

  2. Under Browse, click Settings, then the OneDrive icon titled Fix OneDrive file names

  3. Click Fix to begin the automated process of correcting invalid file and folder names

  4. Once the policy finishes, you'll be notified that file name correction has finished, and given a folder name which contains a backup of your OneDrive directory taken before file name correction began

  5. If OneDrive did not restart automatically, re-open OneDrive from your Applications folder

  6. Click the OneDrive cloud icon (

    ) again; you will hopefully no longer see any sync errors

Optional: Remove backup directory

The Fix OneDrive file names self-service policy will create a backup of your OneDrive directory (FF-Backup-XXXXXX-XXXX, containing the date and time of the backup creation) before attempting to re-name files. In most cases, these backup directories are dataless clone files and do not actually use extra disk space. If, however, you'd like to remove this directory, follow the steps below.

  1. Open a Finder window, click the Go menu at the top of your screen (to the left of the OneDrive cloud icon), and click Go To Folder. Type in "~/" (without the quotes) and press Return; this will take you to your user folder where the backup is stored

  2. Right-click on the FF-Backup directory and click Move to Trash

You may notice a Log in link in the bottom left-hand corner of the CIT Self Service application. It is not necessary to log in to CIT Self Service to run the Fix OneDrive file names policy.

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