Issue Summary
Using Data Migration (New) > Dropbox, the migration job starts successfully but fails with:
Internal error occurred. Code: . Failed to crawl folder for Drive ID: [ID], Folder ID: ns:[ID]
The OAuth connection works (folder paths resolve to valid namespace IDs), but the Dropbox Folder Crawler cannot enumerate folder contents. This affects ALL team folders, not just one.
Environment
- Google Workspace: Super Admin, Customer ID
C02h4hdcw - Dropbox: Business account, Team Admin authorized OAuth
- Migration Target: Shared Drive
Error Details
| Field | Value |
|---|---|
| Source Type | Dropbox Folder Crawler |
| Source URI | drives/3403459395/folders/3403459395 |
| Error Code | Empty (. ) |
| Error | Failed to crawl folder for Drive ID: 3403459395, Folder ID: ns:3403459395 |
Note: The ns: prefix indicates a Dropbox team namespace. Different folder paths resolve to different namespace IDs, confirming path resolution works—but crawling fails on all of them.
CSV Format Used
Source DropboxValue,Target Drive FolderID,Target GUser
/TeamFolderName,[SHARED_DRIVE_ID],admin@domain.com
CSV uploads successfully. Job starts. Crawler fails.
Troubleshooting Completed
| Step | Result |
|---|---|
Fixed CSV format (added leading /) |
CSV accepted, crawler still fails |
| Disconnected/reconnected Dropbox OAuth | Same error |
| Verified Dropbox Team Admin role | Same error |
| Tested multiple team folders | All fail with different namespace IDs |
Timeline
- 2026-01-20 to 2026-01-22: 11 attempts, various folders → all failed
- 2026-01-23: CSV fix, OAuth re-auth → still fails
- Total attempts: 14+
- Successes: 0
Key Observations
- OAuth works: Folder paths resolve to valid Dropbox namespace IDs
- Crawler fails on ALL folders: Not folder-specific
- Empty error code (
Code: .): Suggests internal failure, not user config error - No documentation exists: Searched forums, help docs—no results for “Dropbox Folder Crawler” or this error pattern
Questions for Google
- What does the empty error code (
Code: .) indicate? - Are there known issues with crawling Dropbox Business team folders?
- Are there undocumented Dropbox-side requirements (API scopes, plan tier, admin settings)?
- Can this error be investigated server-side using namespace ID
3403459395?
Request
If others are experiencing this issue, please reply with your error details so we can establish a pattern.
If Google support sees this: the Data Migration (New) Dropbox feature went GA in January 2026, and this error does not appear in any troubleshooting documentation. A resolution or documentation update would help future admins.
Tags: Data Migration, Dropbox, Crawler, Team Folders, Internal Error