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STEP-BY-STEP GUIDE

OneDrive: Fix Invalid File Names and Long Paths

Troubleshooting guideSources checked: 2026-09-055 stepsFaultNote editorial team

What to do first

Fix invalid characters and long paths without deleting content, and check syncing and sharing.

This is a general troubleshooting guide, not an announcement of a current outage.

Affected products and symptoms

Product
Microsoft OneDrive / SharePoint
Versions and conditions
OneDrive for Windows (for personal/work/school use)
Error codes and identifiers
Invalid file nameSync error

Symptoms

  • Name has sync error
  • Why are cloud files not downloading to my PC?

Causes and conditions

Candidates include reserved characters, trailing spaces/periods, reserved names, and excessive path length.

Before you start

  • Copy the question file to another location
  • Record who you shared with and old links

Precautions

  • Do not change the file extension
  • Renaming affects shared links

Tools and official pages used in this guide

Microsoft OneDrive / SharePoint troubleshooting sequence: identify the target; Exclude prohibited characters; Correct the edges and reserved name; shorten the path; See sync and share
Procedure overview created by FaultNote. Read the precautions and full instructions before changing settings. Read the full steps

Step-by-step instructions

  1. 01

    identify the target

    #

    Check the target from the cloud icon synchronization problem and the red X in Explorer.

    Select the cloud icon to open the sync warning and identify the files and folders in error. If you use both personal and work accounts, check which account you want to sync with before changing.

    Select the blue or white cloud in the notification area, open Show sync issues if available, and note the first failed pass. Check the naming rules for one item instead of renaming multiple items at once.

  2. 02

    Exclude prohibited characters

    #

    F2 replaces quotes, asterisks, colons, angle brackets, question marks, diagonal lines, vertical lines, etc.

    F2 is a keyboard operation. Select the target, open Rename, and replace only the offending characters with hyphens, etc. Some names are created from sources other than Windows, so check the actual name against the official list of restrictions.

  3. 03

    Correct the edges and reserved name

    #

    If it is a reserved name, use a different name, excluding leading and trailing spaces and trailing periods.

    Reserved names are special names that cannot be used as regular file names. Even if you change the entire name to a shorter alias, keep the extension. If a file with the same name already exists, do not overwrite it, but choose a name that makes it distinguishable.

  4. 04

    shorten the path

    #

    Move deep folders to a higher level or shorten their names to make room for the entire cloud path (400 characters).

    This includes not only the file name but also the entire path including its parent folders. Since moving a shared folder will affect other users, first shorten the names that you can change and notify other users of the changes.

  5. 05

    See sync and share

    #

    Wait for [Updated] and check the new name on the web, and if the old link is invalid, reshare.

    Once the Explorer warning disappears, check if you can open a file with the same name in the web version of OneDrive. Make sure to check sharing and references from other files, and note the old name and location so you can restore it.

    Official links for this step

Check the result

  • The new name will be the same on the web and PC
  • Share with others too

If the problem continues

  • If there are a large number of errors, a list will be passed to the administrator.
  • After automatic renaming, search from the save location

Scope of this guide

Troubleshooting guide — General diagnostic and recovery procedures based on official support. It does not describe a specific current incident.

Frequently asked questions

Can I use my Japanese name?

Normally you can use it, but be careful with long UTF-8 paths.

Will the content change?

The content will not change, but the old shared link will be affected.

Official sources and dates

Source publication or resolution date: 2026-04-22. Sources checked: 2026-09-05. The check date is not the date the problem first occurred. Interface labels can vary between versions and display languages.

Related troubleshooting guides

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