Resolving “Google Drive was unable to sync this file” (Format)

The error message “Google Drive was unable to sync this file” with a format warning occurs when Google Drive for Desktop encounters a file whose naming conventions, attributes, or container architecture violate cloud file system rules. This prevents the client from pushing the file to Drive or updating an existing cloud copy.

Quick Answer

Rename the file to remove unsupported characters—specifically colons (:), forward or backward slashes (/, \), quotation marks, or trailing spaces and periods. If the file is an unsupported macOS package or an active Office lock file (~$...), compress it into a standard .zip archive or close the source software.

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What Triggers Format Sync Errors?

Google Drive operates a unified cloud storage system that must coordinate file systems across Windows (NTFS), macOS (APFS), and Linux (ext4). When a local file contains attributes or characters supported by your local operating system but rejected by Google’s API, the sync client flags the file as incompatible.

Common Character Conflicts:

Windows NTFS:   Rejects  \ / : * ? " < > |
macOS APFS:     Accepts  : * ? " < > | (creates cloud sync rejections)
Google Drive:   Rejects trailing spaces, trailing periods, and NUL/control characters

The error typically points to one of four issues:

1. Illegal Character Sets: Characters allowed on macOS (like : or forward slashes inside file labels) that violate standard cross-platform API paths.
2. Trailing Periods and Whitespace: Filenames ending with a space (e.g., document .docx) or a period (document.).
3. macOS “Packages” (Directory Bundles): Applications, Keynote files, and complex project libraries (e.g., .app, .logic, .pkg) that appear as single files in Finder, but are actually complex directory trees containing system links.
4. Temporary Lock Files: Hidden temporary files generated by desktop programs (such as Word’s ~$filename.docx or Excel’s .tmp files) that disappear or change state while the sync engine is attempting to read them.

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Step-by-Step Diagnostic and Fix Workflow

Step 1: Clean Illegal Characters and Trailing Pointers

Examine the exact filename flagged in the Drive for Desktop error log:

1. Click the Google Drive icon in your system tray (Windows) or menu bar (macOS).
2. Click the Error / Warning notification banner to display the file list.
3. Locate the file in your local file explorer.
4. Strip out any of the following prohibited characters:
   • Colons (:)
   • Slashes (/ or \)
   • Asterisks ()
   • Question marks (?)
   • Quotation marks (")
   • Angle brackets (< or >)
   • Pipe symbols (|)
5. Check the very end of the file name (just before the extension). Ensure there is no space and no lingering period (change Quarterly Report .docx to Quarterly-Report.docx).
6. Save the name. Drive for Desktop will clear the sync queue automatically.

Step 2: Clear Temporary and Hidden Lock Files

If the failed file starts with a tilde and a dollar sign (such as ~$Proposal.docx), it is not a real document—it is a temporary lock file created by Microsoft Office to prevent simultaneous edits.

1. Close the software (Word, Excel, or PowerPoint) using the file.
2. Once the application exits cleanly, the lock file should automatically delete itself.
3. If the lock file remains behind as an orphaned asset, delete it manually.
4. To prevent these files from cluttering your sync logs, review Troubleshooting .tmp File Sync Bloat in Google Drive.

Step 3: Archive macOS Packages into ZIP Containers

If you are syncing macOS-specific packages, the Drive engine may fail to parse the bundle.

1. Locate the file in Finder (for example, a large Keynote file or an application bundle).
2. Right-click the item and choose Compress “[Filename]”.
3. Move the uncompressed source bundle outside of your local Google Drive sync folder.
4. Leave the newly generated .zip file inside the Drive directory. Google Drive syncs standard compressed archives without issue.

Step 4: Check for Symlinks and Permissions Blocks

If the file name is clean, but the format error persists:

• Verify that the item is not a symbolic link pointing to a file on a disconnected drive; see Troubleshooting Symlink Sync Issues in Drive for Desktop.
• If local file system permissions are preventing the client from reading the format headers, follow Fixing “Can’t sync [Filename]: Access denied” local errors.
• If the file syncs but cannot be opened or previewed in the web interface once uploaded, consult Fix: “Incompatible file type” for Google Drive Preview.