Summary
OneDrive and SharePoint have specific filename restrictions that prevent syncing issues, upload failures, and access problems. Following these rules ensures files work correctly across Microsoft 365 services.
Prerequisites
- Active UTHSC NetID and password
- Access to OneDrive or SharePoint
- Files stored in Microsoft 365 services
Instructions
Invalid Characters
The following characters cannot be used in OneDrive or SharePoint filenames:
Invalid File Endings
Filenames cannot end with:
Reserved Names
The following names cannot be used as filenames, even with an extension:
- CON
- PRN
- AUX
- NUL
- COM1, COM2, COM3, etc.
- LPT1, LPT2, LPT3, etc.
Maximum Path Length
OneDrive and SharePoint support a maximum path length of 400 characters. This includes:
- Site name
- Library name
- Folder names
- Filename
Best Practices
- Use short, descriptive filenames.
- Avoid deep folder nesting.
- Remove special characters before uploading or syncing.
- Rename files locally if OneDrive sync reports an error.
Troubleshooting
- Sync errors: Rename the file to remove invalid characters or shorten the path.
- Upload failures: Check for restricted characters or trailing spaces.
- File not appearing in Teams: Teams uses SharePoint storage, so filename rules still apply.
- Cannot rename: Ensure the file is not open or locked by another user.
Additional Notes
- These restrictions apply across OneDrive, SharePoint, and Teams.
- Fixing filename issues often resolves sync problems immediately.
- Microsoft may update restrictions over time; follow current guidelines when errors occur.
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