One Drive unable to backup due to character name

Hi, Stephen Hoare-Vance

Thanks for reaching out to Microsoft Q&A forum.

Sorry for this unwanted experience that you're having. Here are some brief explanations and workarounds you can try for your current situation:

What OneDrive won’t sync (quick reference)

A name will trigger the “Rename 1 item” banner if it:

• Contains any of: * : < > ? / \ | "
• Starts with a space, a period (.), or a tilde (~)
• Ends with a space or a period (.)
• Is a reserved temporary file (e.g., ~$…) or certain system names (CON, PRN, AUX, NUL, etc. on Windows)
• Is too long: path > ~400 chars, filename > ~255 chars
• Includes Unicode control characters (invisible) or emojis/symbols some apps insert in titles

If an app keeps exporting/creating a file that violates one of these, the OneDrive banner will keep coming back.

Desktop/Documents/Pictures “Backup” issues

Identify the exact item OneDrive dislikes

• In the OneDrive flyout, select View issues > Open folder.
• Sort by Date modified and look for anything recently created with unusual symbols, leading/trailing spaces, or names starting with ~ or ..

Unhide and show extensions

• Open File Explorer > View > enable File name extensions and Hidden items.
• Many problem files are hidden temp files (e.g., ~$MyDoc.docx) or shortcuts.

Remove or safely rename

• Right‑click the file > Rename. Remove forbidden characters, leading/trailing spaces, and period at the end.
• If rename silently fails, copy its contents to a new, cleanly‑named file then delete the original.
• If it’s a shortcut (.lnk or .url) created by an app, delete it and change the app’s setting so it doesn’t auto‑create that shortcut on Desktop/Documents.

Catch items that keep coming back

• Open Task Manager > Startup tab. Disable any app that recreates Desktop links (download managers, printers/scanners, some browsers, game launchers).
• Reboot, then check the folder again.

Quick PowerShell scan for invalid names

Run this in PowerShell inside the problem folder (e.g., your Desktop):

Get-ChildItem -Force | Where-Object {
  $_.Name -match '[\*\:\<\>\?\/\\\|"]' -or
  $_.Name -match '^\s|^\.|^~' -or
  $_.Name -match '\s$|\.$'
} | Select-Object Name, FullName

Anything listed should be renamed or removed.

If nothing is found, you may be hitting path length. Try moving deep folders up closer to the root to shorten the path.

Reset the Backup mapping (if needed)

• OneDrive tray icon > Settings > Sync and backup > Manage backup.
• Turn Off the affected folder (e.g., Desktop), wait 30 seconds, turn it On again.
• This refreshes Known Folder Move and clears stale error state.

Clear a stuck OneDrive client

• Press Win + R, run:

%localappdata%\Microsoft\OneDrive\OneDrive.exe /reset

• Start OneDrive again from Start menu, sign in if prompted.

If the alert still returns after cleanup

Look for duplicate offenders

• Many apps create both .lnk and .url shortcuts, or temp files in the same location. Clean all variants.

Check synced cloud side

• In OneDrive web, open the same folder and see if any serverside items have illegal names (created from another device). Rename there, then let the PC/Mac re‑sync.

Path length

• Deeply nested folders (especially long project names) can silently fail. Move the folder higher up (e.g., C:\Projects\…) and shorten names.

Prevent the issue going forward

• Avoid these characters: * : < > ? / \ | "
• Don’t start names with . or ~. Don’t end with a space or .
• Keep filenames short and meaningful.
• Turn off apps that auto‑drop shortcuts/export files into Desktop/Documents with decorative symbols/emojis.
• Prefer saving to OneDrive\Documents rather than the Desktop for auto‑generated files.

Hope this helps. Feel free to get back if you need further assistance.

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