Different operating systems have different file-naming rules. A file name that works on a Mac may contain characters that are not supported on Windows. This can prevent the file from syncing.
If a file is not syncing due to incompatible characters, rename the file on your computer (or on the web) to remove those characters.
This article covers the following:
- Incompatible characters
- Ignored files
- Live application data, open files, and databases
- Package and bundle file formats
- System folders
- Excluded files
Incompatible characters
Always disallowed in file and folder names:
- / (forward slash)
- \ (backslash)
Not recommended in file or folder names:
Files containing these characters will not sync to Windows computers and may be inaccessible to Windows users through shared folders and links.
- < (less than)
- > (greater than)
- : (colon)
- " (double quote)
- ~$ (tilde dollar sign)
- | (vertical bar or pipe)
- ? (question mark)
- * (asterisk)
- ˆ (circumflex)
- . (trailing period)
- blank space before or after the file name
Note: If you use a Mac and encounter sync errors related to file name characters, update to the latest version of the Mac desktop app. Older versions may have a more restrictive character set.
Ignored files
The Sync apps will not upload or download these file types:
- Path names or path length over 248 characters in total
- desktop.ini
- thumbs.db
- .backupdb
- .cache
- temp files
- ._ files
- .lnk files
- .scriv
- .BridgeCache
- .download
- LPT$ (where $ can be any single digit)
- COM$ (where $ can be any single digit)
- AUX
- PRN
- NUL
- CON
- .DS_Store
- .fcpcache
Live application data, open files, and databases
For more information about live application data, open files, and databases refer to this article: How to resolve files not syncing or stuck indexing in Sync
Package and bundle file formats
Some file types look like a single file, but are actually made up of many individual files and folders. Sync treats these package or bundle formats as separate files, not as one bundled item. Because of this, they may not sync reliably, especially while they are open or being edited.
To reduce issues, close the file before syncing and wait for Sync to finish before opening it on another device. When possible, export or compress the file into a standard single-file (zip) format first.
System folders
Folders like Documents, Library, or system folders from Windows or macOS aren’t supported and shouldn’t be moved directly into your Sync folder. To upload files from these locations, you’ll need to copy the files you want into the Sync folder. Keep in mind that files in your Sync folder won’t automatically sync with other folders on your computer.
Note: Copy to Vault is supported for files from these locations; just keep in mind they won’t stay linked to the original folder.
Excluded files
You can quickly see files that are excluded from syncing through the Sync desktop client.
- Click on the Sync icon located on your Windows system tray (bottom right corner) or Mac OS X menu bar (top right corner)
- Click Preferences
- Click the Progress tab.
- The files will be listed. You can easily navigate to the folder they are in by double clicking the file name.
